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Equipment Discussions >> Cats & Casses

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Phil Hosey
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Why do some consider Hyperstar a 'crude' platform?
      #5818907 - 04/23/13 11:20 PM

It has been recommended that I wean myself from Hyperstar because it is a 'Crude' platform. I'm not saying it isn't, I would like to keep an open mind. If we put aside the difficulties in getting the collimation and focus correct at f/2 which can be quite challenging and if we use a camera that gives us a good image scale, what else technically is wrong with it? Just to be clear, I haven't gotten my Hyperstar system working well yet, it is currently at Starizona along with my C11 being setup. So, in the mean time, I would love to hear the arguments both for and against Hyperstar being a crude imaging platform.

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David PavlichAdministrator
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Phil Hosey]
      #5818935 - 04/23/13 11:38 PM

I'm not sure where that comes from, Phil. Yes, it can be fickle when it comes to getting the adjustments correct. I just had first light with mine. With no collimation and focusing with a Bahtinov mask, the stars looked quite good. The image wasn't worth a hoot, it washed out from the Moon being so close to the object, but the stars looked good. I guess everything is lined up pretty well.

One of the complaints is that using a mono camera with a filter wheel can't happen. Well, with the advent of the QSI cameras with their compact size and internal filter wheel, the 8300 based camera will work well with the C11 and really well with the C14.

It's limited to APS-C or smaller chips and it is hanging on the corrector. But I judge it by the images. For the widefield stuff, it's nice. And for a typical object, a 3 minute exposure sucks in a ton of photons.

Then there's the fact that with a proper reducer/corrector, you can remove the HS and get it down to around f7 and for planetary work, you have the native f10 or f11.

David


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JJK
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Phil Hosey]
      #5818959 - 04/23/13 11:57 PM

What does "crude" mean in this instance?

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mmalik
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Phil Hosey]
      #5819012 - 04/24/13 12:40 AM

Crude is a harsh word but I can't think of a better word for HyperStar; I am not against the creative design of HyperStar per se but I have my concerns about technical and mechanical validity of such a design (i.e., in conjunction with SCT's).

Here are some thoughts where I am coming from:

•SCTs inherently are herky-jerky design (here we go again with another not so optimal word) from collimation to mirror flop to focusers, etc.

•Corrector plate is not a rigid structure in itself and was originally designed to house just the light weight secondary

•HyperStar's fit, i.e., misfit, within the corrector plate gets mentioned quite often; stressing/flexing imparted by HyperStar is another cause for concern

•Nothing against Starizona, but I have my doubts about Starizona's HyperStar design, workmanship, & glass quality... expertise (e.g., consider a “hypothetical” HyperStar offering form Takahashi on top of a corrected Mewlon for a "hypothetical" comparison)

•HyperStar is limited to Celestron ONLY if I understand it correctly; not an SCT-wide acceptance as far as I know (in other word a proprietary offering, not an industry standard)

•Obstructed design of SCT further gets compromised by cumbersome and further obstructing imaging devices used with HyperStar

•Spiking/obstruction caused by traversing connections

•Rigidity of other designs, e.g., refractors, is just not possible in SCTs and HyperStar makes it even less rigid and more prone to stressing built-in tolerances of the SCT system

•Fastness or short circuiting of optical path ramifications of HyperStar are whole another subject that has been discussed at length in another thread...

•Uncorrected optics/folded design of SCTs


I could go on but I think you get the idea... what I am trying to get at is that we have not so optimal/rigid original design of SCT that gets further compromised by HyperStar and that's what makes it NOT so solid and/or sophisticated. HyperStar may suit video or casual still astro imagery, but high quality/high resolution still astro photography remains the domain of un-obstructed and corrected optics. Regards


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JJK
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: mmalik]
      #5819129 - 04/24/13 05:07 AM

Malik, a definition of herky jerky is "spasmodic". That has nothing to do with the optical design of the SCT. Now, Celestron's & Meade's implementation of the primary mirror movement was poor because it led to spasmodic focus movement and mirror flop. However, anyone with decent technical skills can rework the focuser of C or M SCTs if they use a more sensible design (move the primary on a plane defined by three points).

I've been concerned about the stress on the corrector plate caused by a CCD camera. Do you have any data that illustrates this issue?

You also stated that the corrector plate is not rigid (in a non-Hyperstar mode). Please provide solid evidence for that claim.

Edited by JJK (04/24/13 05:10 AM)


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Tapio
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: JJK]
      #5819151 - 04/24/13 05:37 AM

(Certain) Meade SC-scopes can also be used with Hyperstar.
http://www.hyperstarimaging.com/compatibility.php


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bilgebay
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: mmalik]
      #5819185 - 04/24/13 06:00 AM

As an astroimager who has a very satisfactory Hyperstar experience of almost 3+ years I cannot agree with your statement that HS is a crude platform.

•SCTs inherently are herky-jerky design (here we go again with another not so optimal word) from collimation to mirror flop to focusers, etc.

( The new Edge series have mirror locks to deal with the mirror flop )

•Corrector plate is not a rigid structure in itself and was originally designed to house just the light weight secondary

( You don't have to hang a heavy camera to the HS lens. My Atik 460 is only 400 grams. When I used a T2i with my C11 HS, I haven't witnessed any deformation of the corrector by looking at the results the system produced.)

•HyperStar's fit, i.e., misfit, within the corrector plate gets mentioned quite often; stressing/flexing imparted by HyperStar is another cause for concern

( It's not the Hyperstar but secondary holder which is loose to the corrector plate. But this is easy to cure )

•Nothing against Starizona, but I have my doubts about Starizona's HyperStar design, workmanship, & glass quality... expertise (e.g., consider a “hypothetical” HyperStar offering form Takahashi on top of a corrected Mewlon for a "hypothetical" comparison)

( Again I haven't noticed any color aberrations. Sometimes, I get strange reflections but almost all systems have this problem, eg when shooting near Alnitak or Gamma Cass. )

•HyperStar is limited to Celestron ONLY if I understand it correctly; not an SCT-wide acceptance as far as I know (in other word a proprietary offering, not an industry standard)

(Nope, there are HS lenses for Meade SCTs as well)

•Obstructed design of SCT further gets compromised by cumbersome and further obstructing by imaging devices used with HyperStar

( Not necessarily, you can use Pepsi cameras, or make a donut mask to hide the silhouetteof a DSLR. See Samir Kharusi's website for the tips )

•Spiking/obstruction caused by traversing connections

( Not necessarily, there are ways to avoid this. But again, what about Newtonian and RC based astrographs ? )

•Rigidity of other designs, e.g., refractors, is just not possible in SCTs and HyperStar makes it even less rigid and more prone to stressing built-in tolerances of the SCT system

( Quite the contrary... how can you say this after we have discussed for so many pages about FSQ106's shortcoming on this front, which is a "dedicated astrograph" ? I had none of those flexure problems with C11 Hyperstar system )

•Fastness or short circuiting of optical path ramifications of HyperStar are whole another subject that has been discussed at length in another thread...

( This is the whole point... Speed... nothing can beat Hyperstar at this price! )

•Uncorrected optics/folded design of SCTs

( Irrelevant in the context of Hyperstar...I get full flat frame with an APS-C size sensor)

Please continue with your other arguments

Sedat


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JJK
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Tapio]
      #5819224 - 04/24/13 07:02 AM

Quote:

(Certain) Meade SC-scopes can also be used with Hyperstar.
http://www.hyperstarimaging.com/compatibility.php




I didn't suggest otherwise.


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Da Bear
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: JJK]
      #5819283 - 04/24/13 08:21 AM

One of my favorite astro gear stories:

A guy was selling his very expensive, high end scope widget to me and complained endlessly in emails what a stupid design company X had realeased in to the market.

I finally asked about his set up and what he steps he used to get the widget working. After three email exchanges, I figured out he just failed to index the optics, as Company X laid out in the instructions, in bold red letters.

In less than one minute, he finally indexed the "stupid" widget from the "idiots" at company X and it worked perfectly.

Da Bear


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Phil Hosey
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Da Bear]
      #5819299 - 04/24/13 08:47 AM

I for one have no complaints about the design of the Hyperstar and C11. I know my limitations and this time I could not get it working correctly. I do know it is possible though as I have done before with a previous C11 and Hyperstar. That is why I sent both the scope and Hyperstar to Starizona to have Dean set it up. It is now o n the way back to me and should be good to go. There are trade-offs everywhere in this hobby, and I sure love that f/2 imaging and when the Hyperstar is working properly I can accept it's other shortcomings.

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rmollise
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: mmalik]
      #5819347 - 04/24/13 09:25 AM

Quote:



Here are some thoughts where I am coming from:

•SCTs inherently are herky-jerky design (here we go again with another not so optimal word) from collimation to mirror flop to focusers, etc.

•Corrector plate is not a rigid structure in itself and was originally designed to house just the light weight secondary

•HyperStar's fit, i.e., misfit, within the corrector plate gets mentioned quite often; stressing/flexing imparted by HyperStar is another cause for concern

•Nothing against Starizona, but I have my doubts about Starizona's HyperStar design, workmanship, & glass quality... expertise (e.g., consider a “hypothetical” HyperStar offering form Takahashi on top of a corrected Mewlon for a "hypothetical" comparison)

•HyperStar is limited to Celestron ONLY if I understand it correctly; not an SCT-wide acceptance as far as I know (in other word a proprietary offering, not an industry standard)

•Obstructed design of SCT further gets compromised by cumbersome and further obstructing by imaging devices used with HyperStar

•Spiking/obstruction caused by traversing connections

•Rigidity of other designs, e.g., refractors, is just not possible in SCTs and HyperStar makes it even less rigid and more prone to stressing built-in tolerances of the SCT system

•Fastness or short circuiting of optical path ramifications of HyperStar are whole another subject that has been discussed at length in another thread...

•Uncorrected optics/folded design of SCTs


I could go on but I think you get the idea... what I am trying to get at is that we have not so optimal/rigid original design of SCT that gets further compromised by HyperStar and that's what makes it NOT so solid and/or sophisticated. HyperStar may suit video or casual still astro imagery, but high quality/high resolution still astro photography remains the domain of un-obstructed and corrected optics. Regards




Collimation is neither herky nor jerky. A PROPERLY collimated SCT can hold collimation for months or even years. Mirror flop? I've had ONE image ruined by flop over the last 30 plus years. It's not much of a problem, frankly. With current Meades and Celestrons with mirror locks, it is no problem at all. The SCT focuser provides more focus range than any alternative.

There is no doubt you could break a corrector if you banged a camera into something with it mounted in Fastar position. And this has happened to a couple of folks. But not many and that is the bottom line.

The Hyperstars are collimateable.

They appear to have plenty of very satisfied customers. Not sure where you are going with Takahashi, but they don't offer anything like Hyperstar for the Mewlon.

So what? And it WAS offered (the secondary conversion) for Meades for some time.

The quality of Hyperstar images (within the guidelines established for camera/aperture) says otherwise.

These can be minimized. You'll get worse with a Newtonian.

You've mentioned this already, and it is still not a factor.

No idea what "fastness or short circuiting" means... sorry.

Uncorrected what? You do know the supplemental lens that goes in front of a camera in the Hyperstar/Fastar setup is a corrector, don't you?

Nope, I don't get the idea. Are you a Hyperstar/Fastar user? Fastar imaging is not for everyone, no doubt about that. But there is also no doubt it works and works fine as thousands of images taken that way demonstrate.



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jrcrillyAdministrator
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: rmollise]
      #5819363 - 04/24/13 09:33 AM

"Crude" is a subjective term. It's certainly less sophisticated an an RH-200 or an Epsilon, both of which offer far less optical compromise and also permit the use of very large chips and arbitrary camera sizes/shapes. Both are thousands of dollars more than a Fastar-adapted C8, though. If it is crude only compared to those, it is hardly without value.

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jrcrillyAdministrator
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: rmollise]
      #5819368 - 04/24/13 09:36 AM

Quote:

Not sure where you are going with Takahashi, but they don't offer anything like Hyperstar for the Mewlon.




They went in a different (and more Takahashi-like) direction by offering the Epsilon.


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David PavlichAdministrator
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: rmollise]
      #5819379 - 04/24/13 09:39 AM

This image isn't the greatest until you look at the fact that a total exposure time of 100 seconds and the fact that it was an unmodified Canon 40D is what produced the image. I wonder how it would have looked with 30 minutes of exposure using a modified 40D.

Like Rod said, HS isn't for everyone, but it seems to me that those that have used it successfully really like the fact that it takes relatively little time to take the pictures. Used within its limitations, it is a good imaging platform.

David


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Starhawk
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: David Pavlich]
      #5819413 - 04/24/13 10:04 AM Attachment (37 downloads)

Mmalik, you're simply inexperienced with hyperstar. The original design came from the 60" scope on Mount Lemmon. The scope was originally a cassegrain and got a new front end built to allow deep sky searches for asteroids. It has found more than any other telescope. I've had a chance to use it- most galaxies wind up overexposed.

The same person at the University of Arizona here in Tucson designed hyperstar.

It makes it possible to get complete images of a half dozen objects in one night. And your objections just aren't based on reality.

-Rich


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Starhawk
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Starhawk]
      #5819419 - 04/24/13 10:07 AM Attachment (64 downloads)

And here's a detail from that frame:

Note the wee little background galaxies. This is a stack of 30 second images from a Pentax K-5. I was kicking myself for operating at ISO 12800 instead of ISO 51200.

-Rich


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jrcrillyAdministrator
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Starhawk]
      #5819433 - 04/24/13 10:17 AM

Quote:

The original design came from the 60" scope on Mount Lemmon. The scope was originally a cassegrain and got a new front end built to allow deep sky searches for asteroids.




To be fair, that was a classical Cass with a paraboloid mirror at F/4 or thereabouts. All that would be required to switch to prime focus would be removal of the secondary and addition of a coma corrector. Takahashi offered a convertable classical Cass/Newt for years. Converting an SCT with a spherical F/2 primary is much more of a compromise and definitely not the same design.

It's OK to like Hyperstar but let's remain realistic.


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Alph
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: bilgebay]
      #5819610 - 04/24/13 11:54 AM

Quote:

As an astroimager who has a very satisfactory Hyperstar experience of almost 3+ years I cannot agree with your statement that HS is a crude platform.



Didn't you forget to mention that you don't image with the Hyperstar anymore? I see only beginners using the Hyperstar.
How about alignment? Do you expect everybody to go through the same process as you did?


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bilgebay
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Alph]
      #5819630 - 04/24/13 12:06 PM

Nope, where do you get this idea?

I have, just last weekend, purchased a a brand new C8 Edge and a Hyperstar lense for it... Actually I have purchased them 3 months ago but was able to collect them last weekend when I was in US for NEAIC/NEAF.

Do you think I paid so much money not to use it ? You're funny

My problem was the size and weight of my C11 system. I have to tear down my system when I come back to Istanbul. I cannot leave my imaging setup out in the elements unattended for a week or two.


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bilgebay
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Alph]
      #5819639 - 04/24/13 12:09 PM

Quote:

I see only beginners using the Hyperstar.




No problem, you can consider me as a beginner. I am not claiming that I'm a master in this art.


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UnderDriven
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: jrcrilly]
      #5819665 - 04/24/13 12:20 PM

I'm no expert on the HyperStar, but it seems fair to say that it is a "crude" system in the sense that it is a improvised system--meaning that the designers of SCTs never intended that a camera should replace the secondary mirror, and therefore did not take this into account when designing the corrector plate. However, that does not mean that it doesn't work--there have been many improvised systems which have worked well, or at least well enough to accomplish the intended task. As someone else mentioned, every telescope is a compromise...

The only non-improvised system I know of which is nearly as fast as HyperStar is a Takahashi hyperbolic astrograph for $5400. But the Takahashi aperture is only 180mm and it's pretty much a one-trick-pony. Part of the appeal of HyperStar is being able to reconfigure an F/10 telescope as an F/2 astrograph as needed, while spending a lot less than $5400...

Cheers, Keith


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bilgebay
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Alph]
      #5819696 - 04/24/13 12:35 PM

Quote:

How about alignment? Do you expect everybody to go through the same process as you did?




I am not expecting anything Alph. I am only addressing what Mike considers as issues with this system, which, as an actual user, I know that they are not.

My effort to align the optical axis of my C11 Edge was/is an attempt to reach perfection. The system was still useable even before I aligned everything and remember, what i aligned had nothing to do with the Hyperstar lens, it was the secondary and corrector plate to the primary which is an essential parameter even for visual work.

I have bought a multipoint laser collimation tool from Hotech after discussing the possibilty to use this device to optically align all the components of a SCT+Hyperstar system with David. David is willing to invest into this area. The result will be more elegant and we will be sure of aligning the optical axis rather than having to rely on some mechanical properties to support my previous method. Of course, this laser is not cheap but still justifiable.

Lastly, i will really appreciate your sharing the wealth of knowledge you seem to have rather than hitting with negative comments and running. My shooting or not shooting with Hyperstar has no relevance in this context.


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Starhawk
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: jrcrilly]
      #5819950 - 04/24/13 02:42 PM

No stretch, here.

The Mt. Lemmon system is at f/2, now. The lens set for it is about 16" across. The corrector with spherical primary on an SCT already correct for spherical aberration in an SCT. That's why these literally are the same type of system. And it's not a coincidence the same guy designed all of them.

-Rich

Quote:

Quote:

The original design came from the 60" scope on Mount Lemmon. The scope was originally a cassegrain and got a new front end built to allow deep sky searches for asteroids.




To be fair, that was a classical Cass with a paraboloid mirror at F/4 or thereabouts. All that would be required to switch to prime focus would be removal of the secondary and addition of a coma corrector. Takahashi offered a convertable classical Cass/Newt for years. Converting an SCT with a spherical F/2 primary is much more of a compromise and definitely not the same design.

It's OK to like Hyperstar but let's remain realistic.




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Alph
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: bilgebay]
      #5819989 - 04/24/13 03:01 PM

Quote:

My shooting or not shooting with Hyperstar has no relevance in this
context.



The point is that many hyperstar owners move on to other telescopes quite quickly including you . They don’t want to deal with alignment issues every single imaging session. Also the hyperstar f/2 optics has additional inherent shortcomings like vignetting, poor narrowband efficiency, focusing issues, diffraction artifacts caused by cables/camera profile and bloated stars.

Quote:

I have bought a multipoint laser collimation tool from Hotech after discussing the possibilty to use this device to optically align all the components of a SCT+Hyperstar system with David. David is willing to invest into this area. The result will be more elegant and we will be sure of aligning the optical axis rather than having to rely on some mechanical properties to support my previous method. Of course, this laser is not cheap but still justifiable.




I pointed out to David Ho few years ago that the ACT collimator could be used to align the Hyperstar. I had a number of discussions with him about it. He has been very slow in embracing the Hyperstar. I could not convince him to make a mounted mirror that could be threaded on the Hyperstar. Once I even tried to setup a meeting between Starizona and Hotech at a local show, nothing came out of it. Starizona showed very little interest. Personally, I have used the ACT collimator with a blue filter a couple of times to align my 14” HS with mixed results. Squaring the ACT collimator to the SCT is not repeatable.

I think f/2 is simply too fast for narrowband filters and micro-lenses, f/3 would be better, but that's too slow for Starizona (talked to them about it, no plans for Hyperion Hyperstar)


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Starhawk
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Alph]
      #5821168 - 04/25/13 01:00 AM

Micro lenses work at f/1.4. The narrowband filters work, though they can produce unusual flares on bright stars.

Actually, I wonder what the limits are for driving existing hyperstar variants with different primary mirrors. Of course, getting an f/2 parabola isn't trivial.

-Rich


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mmalik
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: rmollise]
      #5821215 - 04/25/13 02:09 AM Attachment (14 downloads)

Quote:

No idea what "fastness or short circuiting" means... sorry.




Good discussion everyone (I am using Rod's comments for elaboration for all); I would like to use this fastness aspect to get a consensus here.

So most of you DO understand what I meant by short circuiting? Simple... regular SCT has three folds of light path, in HyperStar last one gets clipped. Consensus I would like to have is that HyperStar is condensing light of the last fold (in other words converging or bringing to focus) onto the sensor hence giving the appearance of fastness with some loss of resolution/image detail for a given sensor. Do you all agree? If yes, then we are all on the same page with this (whether it is good or bad is a different story).

Now with that said, hypothetically speaking, why not apply this last 1/3 convergence principle to all optics, refractors and all [e.g., imagine clipping last 1/3 of the light cone of a refractor with a "hypothetical" HyperStar for a refractor]; that would be BAD or considered counter productive, correct? If you can understand what I mean then I think I have made my point.


To sum up, then what heck the rest of the astrophotography community is doing with slower, non-HyperStar systems, exposing for long hours... they are getting more resolution than HyperStar would get. That's all; if that's sophistication then one would be justified in calling HyperStar with the 'C' letter word, especially in its current incarnation with SCTs. Regards


Elaboration of last fold condensing/converging by HyperStar:
•Image circle C11: 42mm
•Image circle C11 + HyperStar: 27mm

Edited by mmalik (04/25/13 11:38 AM)


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frolinmod
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: mmalik]
      #5821258 - 04/25/13 02:53 AM

mmalik, there's nothing wrong with a lower effective focal length so long as one has small pixels in his camera as well. Your analogy appears to be flawed.

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Phil Hosey
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: mmalik]
      #5821392 - 04/25/13 07:22 AM

Wait a minute.. The SCT's primary is already at f/2, the Hyperstar isn't condensing anything. Your analogy doesn't seem to make sense to me. You are comparing a refractor being reduced to f/2 to a system that is natively f/2. Maybe I'm missing something in your argument. I need a more thorough explanation.

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rmollise
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: mmalik]
      #5821459 - 04/25/13 08:33 AM

Quote:



So most of you DO understand what I meant by short circuiting? Simple... regular SCT has three folds of light path, in HyperStar last one gets clipped. Consensus I would like to have is that HyperStar is condensing light of the last fold onto the sensor hence giving the appearance of fastness with some loss of resolution/image detail for a given sensor. Do you all agree? If yes, then we are all on the same page with this (whether it is good or bad is a different story).




Sorry Malik... This is not correct. There is no "condensing of light" (whatever that might be). The bottom line is that the primary mirror of the SCT is being used at its normal, native focal ratio, about f/2. No unfolding or magic at all, you see.

Edited by rmollise (04/25/13 09:55 AM)


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: rmollise]
      #5821621 - 04/25/13 09:37 AM

Rod,
I thought the SCT corrector plate is what is correcting for the spherical mirror and that the Hyperstar lens is correcting for other abberations such as coma and flattening the field. I don't think the Hyperstar is correcting spherical abberation.


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rmollise
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Phil Hosey]
      #5821673 - 04/25/13 09:54 AM

Quote:

Rod,
I thought the SCT corrector plate is what is correcting for the spherical mirror and that the Hyperstar lens is correcting for other abberations such as coma and flattening the field. I don't think the Hyperstar is correcting spherical abberation.




You are right, Phillip...I got carried away.


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ghataa
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: rmollise]
      #5821824 - 04/25/13 11:22 AM

For me, sometimes you just have to look at the data. There are so many incredible images taken with the Hyperstar approach that it seems like a nice addition to an imager's toolbox. Like a lot of things in life, it's a choice. I don't own a Hyperstar but would love to have such a system!

Best,

George


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: ghataa]
      #5822177 - 04/25/13 01:32 PM

I really love the short exposure times, especially on a borderline adequate Ultima fork mount. Without a permanent pier or observatory, and Polar alignment that is so-so, it makes imaging for beginners like me easy and satisfying. I haven't used it for video yet, but I hear it does rather well in that regard. That being said, the $800 HS and $300 conversion is a tough pill to swallow. I would feel more justified if I could figure out a way to Barlow it to F/4. That would make a lot more objects available.

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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: J. Barnes]
      #5822357 - 04/25/13 02:54 PM Attachment (40 downloads)

I have to put my two cents in. I have the system, due to work/deployments and crummy German weather, I've only been able to use it once since I bought it a year ago. Here is my first image, the only processing was done with the nightscape astro fx software. I am a total amateur with no other imaging experience. It's easy to use and it works, and in my opinion relatively inexpensive. Oh, and don't forget, it's tons of fun.

I'm moving to norther California soon, I can't wait to get out to some dark skies, away from the clouds and light pollution here, and try my hand at some more imaging.


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Starhawk
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Wilki]
      #5822440 - 04/25/13 03:38 PM

MMalik, I think the misunderstanding here goes all the way back to what the telescope does in the first place.

I'm thinking we should maybe start by discussing what a SCT is, and then we can move on to what hyperstar does differently.

The original device in the series was something called a Schmidt camera, which had a camera facing a primary mirror with a corrector in front of the entire assembly. This was in the film days, and the telescope was made to stretch the film to curve it into the shape of the focal plane.

The Schmidt telescope was a modification of this concept where a secondary mirror was added to make a multi-purpose telescope.

An SCT has a corrector matched to an f/2 primary mirror (on most, f/2.3 on a C9.25). This paired set produces a short light cone going to the secondary, again at f/2.

The curved secondary mirror acts as an f/5 barlow and stretches the light cone out to an f/10 cone, although there is still coma present due to the curvature at the focal plane.

Now, looking at this, it is apparent a complete telescope is possible by mounting a camera at the focus of the primary.

In fact, this design is simply reverting to the original Schmidt camera, but the main problem it had is the film needed to be stretched to match the curved focus surface.

The fastar device appeared as a flattener to allow a flat chip to take the image from the Schmidt optics and focus it on a flat surfaced imager.

Now, Hyperstar is an expansion of that concept to support larger sensors.

So, saying hyperstar is a crude platform is really missing much of the point behind it.

Now, in the world of modern telescope versions, the Celestron Edge was purposey designed to be compatible with hyperstar. That was one reason for putting the flattening optics into the baffle tube- so the telescope could revert to being a Schmidt camera.

The Meade ACF was not designed to be compatible with hyperstar, and the change to the prescription broke the commonality with a Schmidt camera which allowed a flattener to take the place of the secondary. This is why Meade Hyperstar variants have disappeared.

Anyway, as I hope you can now appreciate, the hyperstar setup is actually a very elegant solution to a difficult problem, and offers remarkable performance with modern cameras.

-Rich


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Starhawk]
      #5822455 - 04/25/13 03:49 PM

Quote:

The Schmidt telescope was a modification of this concept where a secondary mirror was added to make a multi-purpose telescope.




...and the corrector was relocated to about 1/2 the ideal distance from the primary. That's where SCT coma comes from.


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J. Barnes
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Wilki]
      #5822482 - 04/25/13 04:09 PM Attachment (39 downloads)

Quote:

I am a total amateur with no other imaging experience. It's easy to use and it works, and in my opinion relatively inexpensive. Oh, and don't forget, it's tons of fun.

I'm moving to norther California soon, I can't wait to get out to some dark skies, away from the clouds and light pollution here, and try my hand at some more imaging.



I'm with you there. I shot this single 30 sec. exposure through a brief "sucker hole" that opened up the other night.
Collimation on? Doesn't look like it.
Polar aligned? Sort of. (I saw Polaris for about 20 seconds)
Stange abberation?
Better than eyepeice projection a year ago?
In a couple of years my response?


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Starhawk
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: jrcrilly]
      #5822896 - 04/25/13 07:38 PM

You are correct, of course, and there are telescopes originally configured as Schmidt cameras which now have an internal flattener and CCD installed to turn them into astrographs. The 30" scope on Mount Bigelow matches this description.

-Rich

Quote:

Quote:

The Schmidt telescope was a modification of this concept where a secondary mirror was added to make a multi-purpose telescope.




...and the corrector was relocated to about 1/2 the ideal distance from the primary. That's where SCT coma comes from.




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Starhawk
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Starhawk]
      #5822918 - 04/25/13 07:49 PM Attachment (44 downloads)

Here is an Orion Nebula I did with the Pentax K-5 on C-11 hyperstar.

-Rich


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Starhawk
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Starhawk]
      #5822923 - 04/25/13 07:50 PM Attachment (39 downloads)

Here is the upper left hand corner.

-Rich


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Starhawk
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Starhawk]
      #5822935 - 04/25/13 07:53 PM

I have a donut shaped collimating tool made from Dean's collimator for the hyperstar he did for the ISS. The circular donut hides the camera and produces an ideal bullseye pattern for collimating the hyperstar. I no longer need to collimate every time I set up.

-Rich


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jrcrillyAdministrator
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Starhawk]
      #5822951 - 04/25/13 08:08 PM

Quote:

You are correct, of course, and there are telescopes originally configured as Schmidt cameras which now have an internal flattener and CCD installed to turn them into astrographs.




Officina Stellare used to (and may still) sell such an instrument for amateur use.


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Phil Hosey]
      #5823097 - 04/25/13 08:56 PM

Here is a single sub I did with the previous Hyperstar setup I had back in 2011. It's a single 30 second unguided shot with the a Canon XSi. 30 seconds was all I needed to get sky fog limited. If I can get the current Hyperstar to perform like this consistently I'll keep it.


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: jrcrilly]
      #5823188 - 04/25/13 09:29 PM

I don't consider myself an expert by any means. In fact I'm little more than a beginner having been in this hobby for a bit less than two years. For me Hyperstar has been incredible! There isn't another system that would allow you to get all of the following in a single night and with an unmodified Nikon D7000, all from stacks of 30second, unguided, exposures:

Cocoon Nebula: http://www.astrobin.com/full/21509/
Horse & Flame: http://www.astrobin.com/full/21521/
Double Cluster: http://www.astrobin.com/full/21523/
Trifid & Lagoon: http://www.astrobin.com/full/21525/
Omega: http://www.astrobin.com/full/21526/
Andromeda: http://www.astrobin.com/full/21528/
Triangulum: http://www.astrobin.com/full/21529/
Pleiades: http://www.astrobin.com/full/21534/
Orion: http://www.astrobin.com/full/21533/

Later I moved to a 60Da and got an H-alpha filter and was able to get this from my backyard which is a white zone:

Rosette: http://www.astrobin.com/full/32724/

None of this is going to get published, but I find it an immensely satisfying setup.

As a side note, I have never collimated my Hyperstar. Whatever it was set to from the factory I've used untouched.


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milby
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: end]
      #5823387 - 04/25/13 11:44 PM

FYI, there is an active thread elsewhere on the forum discussing the Hyperstar system: http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/5695352/page...

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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Phil Hosey]
      #5823528 - 04/26/13 02:29 AM

Quote:

Why do some consider Hyperstar a 'crude' platform?




Because they are disinformed, misinformed or not informed at all!

Efforts to convince them are futile I believe.


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mmalik
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Starhawk]
      #5823559 - 04/26/13 03:53 AM

Quote:

An SCT has a corrector matched to an f/2 primary mirror (on most, f/2.3 on a C9.25). This paired set produces a short light cone going to the secondary, again at f/2.




Good information Rich, but documentation I have seen from Celestron... mentions f/2 only in reference to and/or in conjunction with HyperStar (not natively or independently of HyperStar).


Does anyone have links to HyperStar architecture diagrams/PDFs? Thx


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Phil Hosey
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: mmalik]
      #5823642 - 04/26/13 06:14 AM

Quote:

Quote:

An SCT has a corrector matched to an f/2 primary mirror (on most, f/2.3 on a C9.25). This paired set produces a short light cone going to the secondary, again at f/2.





Good information Rich, but documentation I have seen from Celestron... mentions f/2 only in reference to and/or in conjunction with HyperStar (not natively or independently of HyperStar).


Does anyone have links to HyperStar architecture diagrams/PDFs? Thx




Maybe that's because for most users the net result is what matters, that is, the scope is f/10 (f/11 for the C14). The fact is that the primary on SCTs is very fast f/2 for the C11 in my case. The Hyperstar was designed to correct the remaining abberations after the SCT corrector does its job on the f/2 primary. The Hyperstar is not a reducer.


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mmalik
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Phil Hosey]
      #5823699 - 04/26/13 07:18 AM

Not arguing; would like to see two types of documents/data if anyone can help provide for better understanding:

1. HyperStar architecture diagrams/documentation to that effect (that it is not a reducer)
2. Celestron documentation stating native f/2 primary (without mention of HyperStar in the same documentation)


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: mmalik]
      #5823713 - 04/26/13 07:38 AM

I suggest the recent book by Smith, Ceragioli, and Berry. You can also look at the Edge Whitepaper released by Celestron. I think it's well known that all the major sct's use f/2 primaries except the c9.25, which is around f/2.3.

Hyperstar is a follow-on to Fastar and has had several iterations. Unfortunately I have version II of hyperstar for my c11 and although it is a step up from the version 1 in terms of adjustments, I think the latest version III is much better.

The book I mention has some discussion of Hyperstar and although I don't have it here, one thing they mention is the benefit obtained from the use of particular glass types specific to the design. In that sense I don't think it should be viewed as a generic or duplicated solution, but as a specific design intended to correct the field of each OTA. It also differs from typical prime focus Newtonian correctors in that it needs to be very compact to hang off the front - and the compactness motivates the need for exotic glasses and corresponding expense.

I don't think it's trivial to flatten such a large and fast field in a short space and it's clear that it does the job well.

I haven't used mine much because it is the version II type and I don't get very good correction across the field. Results by others with the latest version, and with care laying out the wires so the stars don't show artifacts, look good and have measurably small stars across the field.

Frank


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Phil Hosey
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: mmalik]
      #5823860 - 04/26/13 09:21 AM

Quote:

Not arguing; would like to see two types of documents/data if anyone can help provide for better understanding:

1. HyperStar architecture diagrams/documentation to that effect (that it is not a reducer)
2. Celestron documentation stating native f/2 primary (without mention of HyperStar in the same documentation)




It is well known that SCTs use fast spherical primary mirrors, you can even just look at the mirror and tell that it is a fast mirror. It follows from this that if you were to remove the secondary and place a camera at the focus of the primary then you're at f/2 (2.3 for the C925Z). Not sure why you insist on having some documentation in this case to tell you the obvious.


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Phil Hosey]
      #5823883 - 04/26/13 09:31 AM

Starizona web site gives this info already, they are the makers of the lens so we should trust the info listed on their website:

C6 - f/1.9
C8 - f/2.1
C9 - f/2.3
C11 - f/2.0
C14 - f/1.9

Any other questions ?


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: mmalik]
      #5823899 - 04/26/13 09:39 AM


Try this link. Celestron states the in there that the primary is f/2 and explains what abberations the Fastar/Hyperstar lenses correct.


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Phil Hosey]
      #5824072 - 04/26/13 10:46 AM

MMalik,

I'm not sure what you're asking. Do you feel the SCT prescription is in doubt? You can just google Schmidt telescope and Schmidt camera and read away. Or, you can do the more direct path and get a tape measure. If the primary mirror wasn't f/2, you could tell because the telescope would have to be longer (like a Newtonian) to get the light from the edge of the mirror to the secondary. This is why the SCT in commercial production is called the compact form.

I suggest you convince yourself. You'll learn more and have complete confidence in the answer. You'll also learn a lot about where the design came from, and that's always a good thing.

-Rich

Edited by Starhawk (04/26/13 10:58 AM)


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mmalik
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Phil Hosey]
      #5824908 - 04/26/13 05:07 PM

Quote:

Try this link. Celestron states the in there that the primary is f/2 and explains what aberrations the Fastar/HyperStar lenses correct.




Phil/Rich/all, thanks for all the feedback; it appears primary mirror on Celestron is ~f/2 contrary to what my understanding of HyperStar doing bulk of the reduction. I stand corrected on that point!

But let me be clear here... that fastness of f/2 primary (in other words sharp convergence of light cone regardless of where it happens) comes at a cost; loss of resolution and image detail at the expense of brighter image [let’s leave the pixel size/density of a sensor out of it for a minute]. Again, I am and have been trying to make a technical point and not a repudiation of HyperStar design per se, that I think most of us can agree on. Do you?

HyperStar seems to be optimized for one and one SCT platform only and that is Celestron (for all practical purposes). If this is such a revolutionary idea, why it hasn’t caught fire with the rest of the SCT and other folded design optics (CDK, etc.) I think it should if it really is that revolutionary?

Let’s go one step further, if sharp coning at f/2 at larger apertures is all the hype about HyperStar, then why not reduce unobstructed optics of refractors with the similar concept and let’s all be exposing at HyperStar speeds? With high density and small size pixel sensors available these days, does it make sense to start reducing all optics to HyperStar levels? Remember, my main argument has been HyperStar implementation on less than optimal (folded/flopping/collimate-able) and obstructed design of SCT. Regards


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David PavlichAdministrator
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: mmalik]
      #5825024 - 04/26/13 06:25 PM

Hyperstar and anything that is very fast (Tak Epsilon and the Powernewt come to mind) do well with that big widefield stuff. Not everyone wants to image at that scale. More so than not, larger image scale is desired.

Having said that, you see that companies like Planewave make reducers to get that extra speed and a wider field.

Like has been said, Hyperstar isn't for everyone. It has limitations, but if you find these limitations ok, it does a pretty good job.

David


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Patrick
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: David Pavlich]
      #5825229 - 04/26/13 08:03 PM

I have to agree with David. I've got two SCT's, a C11 and a HD8, as well as an AT66ED refractor, and I've had a hard time justifying spending telescope money to upgrade to the Hyperstar system. It's a tough choice between Hyperstar and my AT66ED refractor. The refractor with a 0.8x flattener/reducer is f/4.8 and 320mm f/l and I can use my DSLR with it without casting a shadow on the primary mirror. I don't think there's anything I could take with the Hyperstar that I can't take with the refractor. It may just take a little longer.

Having said that, I'm still intrigued by the Hyperstar...my HD8 with Hyperstar would be f/2.1 and 425mm f/l. That is an interesting combination. If I just had a suitable CCD camera, dag nabbit.

...man this hobby can be pretty expensive.

Patrick


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: mmalik]
      #5825394 - 04/26/13 10:05 PM

MMalik,

I guess we're making progess of a sort. So, here we go:

Resolution is a function of aperture and only aperture. So, the reason the Large Synoptic Survey Telescope is being built is to get an 8 meter resolution image on an 8 degree field. In this case, it's a three mirror telescope with the camera looking into the front.

The speed of the optic is working on what its image scale is, and that's where the f/# comes in.

The bigger question is what does f/# mean for images, anyway? So, the answer is, image brightness is inveresely proportional to the f/#. In order to turn this into tangible numbers, I have been using a non-dimensional brightness factor.

Br= 1000/(f/#)^2

So, here are some examples:

f/10 SCT: Br= 1000/(10)^2 = 1000/100 = 10

AT66ED: Br= 1000/(6)^2 = 1000/36 = 27.777

So, the image from an AT66ED is 2.777 times brighter than the image from an SCT at the f/10 prime focus. Now, you may be wondering what gives with the radically different diameters of 4", 5", 6", 8" 10", 11" nd 12" f/10 SCTs all having the same brightness coefficient, where a wee little 66mm refractor could be claimed to produce a brighter image. so, here is what you need to know: All optics with the same f/# have the same image brightness. This is why camera lenses only give their f/# range and no one really cares what the aperture diameter is except for buying filters.

So, SCTs do have a reducer, and there are lots of scopes floating around, so lets look at the image brightness factors:

Intes 150mm f/12 maksutov 6.94
Celestron C8 @ f/10 10
Orion ED80 f/7.5 17.77
Celestron C8 @ f/6.3 FR 25.19
AP 130 EDFGT f/6.3 25.19
AP 130 EDFGT f/4.75 FR 44.32
Orion ST 80 f/5 40
Orion f/4 Newtonian 62.5
f/3.57 5.5" Schmid newt 78.46
C11 Hyperstar @ f/2 250

So, as you can see, relatively small moves in the f/# changee the f/# in a big way. This is why people like AP, TEC, Tak, and Televue have all had an ongoing battle to produce faster refractors.

I have a spreadsheet based on this I have used to evaluate imaging setups before getting them. Note, you can directly predict improvement in magnitude penetration by change in brightness coefficient, where a factor of 2.5 will give another magnitude dimmer penetration at the same exposure time. So, for example, going from f/10 to f/6.3 can take you from magnitude 18 to magnitude 19. Going from f/10 to f/2 is 3.6 magnitudes.

As for the question of why there aren't lots of things like Hyperstar all over the place, well, in fact there are. A lot of them aren't fully obvious today becase they date from the film era. Others like the LSST just aren't on your radar. But, for example, the Hale telescope was originally used by exposing plates with a manned cage in the secondary.

As for trying to do this with other kinds of telescopes, you would have to have one with a primary optic as fast as the one in a compact SCT to do the trick. Up to now, those have been the domain of the SCT exclusively.

Refractors can only get to f/2 class speeds in small diameters with lots of otpical elements unless they only operate with monochromatic light. Some other reflector designs get down to f/1, but we are talking about very special setups with price tags an order of magnitude higher than an SCT/hyperstar combo.

Look around and gather info. You'll see what is going on.

-Rich

Quote:

Quote:

Try this link. Celestron states the in there that the primary is f/2 and explains what aberrations the Fastar/HyperStar lenses correct.




Phil/Rich/all, thanks for all the feedback; it appears primary mirror on Celestron is ~f/2 contrary to what my understanding of HyperStar doing bulk of the reduction. I stand corrected on that point!

But let me be clear here... that fastness of f/2 primary (in other word sharp convergence of light cone regardless of where it happens) comes at a cost, loss of resolution and image detail at the expense of brighter image [let’s leave the pixel size/density of a sensor out of it for a minute]. Again, I am and have been trying to make a technical point and not a repudiation of HyperStar design per se, that I think most of us can agree on. Do you?

HyperStar seems to be optimized for one and one SCT platform only and that is Celestron (for all practical purposes). If this is such a revolutionary idea, why it hasn’t caught fire with the rest of the SCT and other folded design optics (CDK, etc.) I think it should if it really is that revolutionary?

Let’s go one step further, if sharp coning at f/2 at larger apertures is all the hype about HyperStar, then why not reduce unobstructed optics of refractors with the similar concept and let’s all be exposing at HyperStar speeds? With high density and small size pixel sensors available these days, does it make sense to start reducing all optics to HyperStar levels? Remember, my main argument has been HyperStar implantation on less than optimal (folded/flopping/collimate-able) and obstructed design of SCT. Regards




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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Patrick]
      #5825403 - 04/26/13 10:15 PM

As a total newbie, you much more experienced and professionally/semi professionally equipped members can brush off my comments with either disdain or a snicker. No bother to me. But to watch you guys go back and forth is truly entertaining (no insult intended). You are ALL capturing images I can only hope to one day have the ability and equipment to achieve. I've always been a "results are what matters" kinda guy. The examples of the pics taken with the Hyperstar, "crude" or not, are simply stunning. I have only re-entered this hobby recently after a more than 30 year hiatus. My God, things have changed! It has apparently come so far that these conversations are amusingly taking on the atmosphere of a "hoity toity" fine wine tasting event. I am still enjoying the awe of it all, the joy of it all, the wonder of it all. I hope none of you ever lose that. Whether looking through a table top dob, or one of the incredible pieces of equipment you have been fortunate enough to acquire. Thanks for the chuckle. Clear skies. Chaz

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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Chaz659]
      #5825437 - 04/26/13 10:37 PM

Not to put too fine a point on it, Chaz, but the guy calling it "Crude" is the one not posting any images.

Just saying....

-Rich


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: mmalik]
      #5825633 - 04/27/13 02:38 AM

Quote:

Remember, my main argument has been HyperStar implementation on less than optimal (folded/flopping/collimate-able) and obstructed design of SCT.




Like others I'm not sure exactly what you're asking - but you seem to imply that the lack of large aperture f/2 systems indicates a lack of a market, or that such a system is inherently inferior. Instead I would say that such systems are difficult to make with a large, flat, and color corrected field - which is why Hyperstar stands out. It clearly has disadvantages - mainly in needing a smaller camera, and the awkwardness of hanging a camera off a thin piece of glass - which is very unusual and somewhat scary the first time.

I do own an f/2 refractor: a Canon 135mm f/2 L lens. It is a great lens but it is small aperture and over $1000. Plus, it is not diffraction limited and would need to be stopped down a bit for astro use. The Canon 400 f/2.8 is extremely expensive and already much slower than f/2.

There are no large aperture f/2 pure lens systems corrected over a wide field that I know of for amateur use - presumably because the cost and weight would be prohibitive.

As for the desire to have a fast, wide angle system - that is exactly what is desired in a "survey" telescope - where the performance metric is A-Omega - the aperture area times the solid angle of the imaging field. This is proportional to ImageArea/FNum^2 - i.e. you just want a big detector and fast optics.

A good example of a professional system with that in mind is the LSST, which is 8.4m aperture, f/1.2 - and will have the largest convex mirror ever made. It uses a third mirror in a Paul-Baker configuration - with corrective lenses near the detector - but the general idea of using mirrors and lenses is the same. Obviously there is little need for Hyperstar above about 16" because people don't tend to make sct's or anything that requires a large lens in the front.

On the amateur market there is the Officina Stellare 200 mm f/3 - and it costs a bundle.

With any system that has relatively large pixels, in arc-seconds, there will be a loss of resolution from under-sampling - but that is the trade off you need to make. It's not so much due to speed or f/ratio, but the shorter focal length.

In short - yes, many people do want large aperture, fast optics - and would probably love such a thing at low cost in a pure lens system - but such a thing does not exist on the market due to its inherent difficulties. To quote Smith, Ceragioli, Berry, "The Hyperstar has thus assumed the mantle of the Schmidt camera for modern amateur astro-imagers."

Frank


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: freestar8n]
      #5825707 - 04/27/13 05:37 AM

Quote:

@freestar8n: It clearly has disadvantages - mainly in needing a smaller camera, and the awkwardness of hanging a camera off a thin piece of glass - which is very unusual and somewhat scary the first time.

...

In short - yes, many people do want large aperture, fast optics - and would probably love such a thing at low cost in a pure lens system - but such a thing does not exist on the market due to its inherent difficulties. To quote Smith, Ceragioli, Berry, "The HyperStar has thus assumed the mantle of the Schmidt camera for modern amateur astro-imagers."




Quote:

@UnderDriven: it seems fair to say that it is a "crude" system in the sense that it is a improvised system--meaning that the designers of SCTs never intended that a camera should replace the secondary mirror, and therefore did not take this into account when designing the corrector plate. However, that does not mean that it doesn't work--there have been many improvised systems which have worked well, or at least well enough to accomplish the intended task. As someone else mentioned, every telescope is a compromise...




Quote:

@Patrick: The refractor with a 0.8x flattener/reducer is f/4.8 and 320mm f/l and I can use my DSLR with it without casting a shadow on the primary mirror. I don't think there's anything I could take with the HyperStar that I can't take with the refractor. It may just take a little longer.




Frank, I like the way you put it; pretty much what I have been trying to say all along. Also as Keith put it, it is an "improvised" system after all... an afterthought of sort. I would love to see something of f/2 caliber in a "pure lens system".


I just don't consider SCT a sound enough, solid enough platform to house HyperStar and the works. Personally, I would like to see HyperStar mating with CKD platform, for example, of Takahashi caliber (Mewlon 250, 300).


What would be even better... a CDK purposed/corrected for ~f/2 where one could just plug-in the camera at the secondary, without the need of intervening HyperStar. Now that will be something! ...a prime-focus HyperImaging system but without actual HyperStar correcting elements being there. I consider current HyperStar implementation an equivalent of a ‘fast’ eye-piece projection of sort. Regards


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: mmalik]
      #5825726 - 04/27/13 06:06 AM

Quote:

I would love to see something of f/2 caliber in a "pure lens system".




If you want to dream - why stop there? I would like the light collection of the Keck telescope in a small device that I can fit in a shirt pocket. The thing you are asking for does not exist because it is too difficult, heavy, and expensive to make.

Quote:

I just don't consider SCT a sound enough, solid enough platform to house HyperStar and the works. Personally, I would like to see HyperStar mating with CKD platform, for example, of Takahashi caliber (Mewlon 250, 300).




You seem to complain about mirror flop and such - when sct imaging done properly don't show any deleterious impact from it. As long as the telescope is pointing up the mirror weight is steady and any slow change will not impact the typically short hyperstar exposures. At long focal length, I use OAG with sct and I also get no impact from the "crude" focusing system. The only time it is a problem is when using a guidescope in long exposures - but that applies to high end systems that still require oag for best results despite expensive mechanics and even glued mirrors, as in the case of cdk.

High end astrographs tend to use primaries that are at least f/3 because it makes it easier to flatten the field. This means that if you want f/2 you would need an additional reduction, and that is problematic with lenses due to chromatic aberration.

Replacing the secondary with hyperstar may be a bit awkward, but it only takes a few seconds and is easy to collimate, whereas taking the secondary off the spider of a cdk, for example, and somehow attaching a long and heavy optical system with a camera attached seems very problematic - and again would only get you f/3 or so.

I believe Ceravalo has a more high end version of a cdk that converts between f/4.9 and f/9, and it has a large secondary and costs a lot - and still only gets you to just under f/5.

The fact is that Edge with both hyperstar and reducer is still well below the cost of the high end systems you allude to, yet it provides a wide and flat field at f/10, f/7, and f/2 - and it achieves diffraction limited imaging at f/10 and f/7, and at least seeing limited imaging at f/2 - with no real impact from the mirror mechanics. It's relatively low cost, versatile, and easy to switch between modes - once you get used to attaching hyperstar.

But no - an Edge14 Hyperstar is not a magic 14" f/2 lens system with no secondary obstruction like my +$1000, 72.5mm diameter canon f/2 lens.

Frank


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: mmalik]
      #5825932 - 04/27/13 09:29 AM

Quote:

Quote:

@freestar8n: It clearly has disadvantages - mainly in needing a smaller camera, and the awkwardness of hanging a camera off a thin piece of glass - which is very unusual and somewhat scary the first time.

...

In short - yes, many people do want large aperture, fast optics - and would probably love such a thing at low cost in a pure lens system - but such a thing does not exist on the market due to its inherent difficulties. To quote Smith, Ceragioli, Berry, "The HyperStar has thus assumed the mantle of the Schmidt camera for modern amateur astro-imagers."




Quote:

@UnderDriven: it seems fair to say that it is a "crude" system in the sense that it is a improvised system--meaning that the designers of SCTs never intended that a camera should replace the secondary mirror, and therefore did not take this into account when designing the corrector plate. However, that does not mean that it doesn't work--there have been many improvised systems which have worked well, or at least well enough to accomplish the intended task. As someone else mentioned, every telescope is a compromise...




Quote:

@Patrick: The refractor with a 0.8x flattener/reducer is f/4.8 and 320mm f/l and I can use my DSLR with it without casting a shadow on the primary mirror. I don't think there's anything I could take with the HyperStar that I can't take with the refractor. It may just take a little longer.




Frank, I like the way you put it; pretty much what I have been trying to say all along. Also as Keith put it, it is an "improvised" system after all... an afterthought of sort. I would love to see something of f/2 caliber in a "pure lens system".


I just don't consider SCT a sound enough, solid enough platform to house HyperStar and the works. Personally, I would like to see HyperStar mating with CKD platform, for example, of Takahashi caliber (Mewlon 250, 300).


What would be even better... a CDK purposed/corrected for ~f/2 where one could just plug-in the camera at the secondary, without the need of intervening HyperStar. Now that will be something! ...a prime-focus HyperImaging system but without actual HyperStar correcting elements being there. I consider current HyperStar implementation an equivalent of a ‘fast’ eye-piece projection of sort. Regards




If you throw enough money at something, you can make it work. Problem is, most companies work on ROI. How many pure f2 systems could someone sell considering the final cost? I'd be willing to bet that it wouldn't be enough for someone to invest that kind of capital to have a fully functioning system and sell enough of them to get a manageable return. We already have examples of very expensive f2 lenses hanging on Canon and Nikon camera that cost more than a C11 Edge AND a Hyperstar. And it's "just" a camera lens.

David


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: David Pavlich]
      #5825945 - 04/27/13 09:44 AM

I have a question and it may have been answered before but what about a HS capable RC? I don't see why that isn't at least possible? Haven't given it much thought other than I don't recall seeing any retrofit spiders out there for the typical AT / GSO class tubes. Just wondering ...

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Phil Hosey
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: BlueGrass]
      #5825982 - 04/27/13 10:16 AM

Quote:

I have a question and it may have been answered before but what about a HS capable RC? I don't see why that isn't at least possible? Haven't given it much thought other than I don't recall seeing any retrofit spiders out there for the typical AT / GSO class tubes. Just wondering ...




How hard would it be to make an f/2 hyperbolic mirror? The thing is, SCT primaries are spherical, much easier to make at f/2.


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Phil Hosey]
      #5826018 - 04/27/13 10:42 AM

Quote:

It has been recommended that I wean myself from Hyperstar because it is a 'Crude' platform. I'm not saying it isn't, I would like to keep an open mind. If we put aside the difficulties in getting the collimation and focus correct at f/2 which can be quite challenging and if we use a camera that gives us a good image scale, what else technically is wrong with it? Just to be clear, I haven't gotten my Hyperstar system working well yet, it is currently at Starizona along with my C11 being setup. So, in the mean time, I would love to hear the arguments both for and against Hyperstar being a crude imaging platform.




'Crude' isn't, in my opinion, a good description. Does it have pros and cons? Of course it does. Any imaging platform does.

Pros:
  • Extremely fast, so allows image depth with extremely short integration time
  • Very short subexposures to shot noise limit which may allow one to bypass autoguiding entirely (and puts less strain on the mount in general with respect to tracking accuracy)
  • Allows wide fields to be captured with what is normally a scope with a fairly narrow field of view (both a pro and a con, depending on what you like to image)
Cons:
  • Only supports relatively small image circle
  • Almost requires a one-shot-color camera since there is no room for a color filter wheel
  • Not a great match for emission line imaging since, again, there is no room for a color filter wheel--you'd need a second, monochrome camera
  • Finicky about getting the optical alignment right despite the fact that it's a wide field system
  • Only available for certain model SCT's
  • May be difficult to get and maintain focus since the depth of focus in absolute terms is so limited


I think it's an ingenious way to solve a particular problem. You want wide fields of view? You want short integration time for a given image depth? You want to do RGB imaging? It's a great choice.

You want to image planetary nebulae? Or galaxies (with a few large exceptions)? Or globulars? Or narrow band imaging? Then, I'd say, it's a pretty poor choice. Nothing to do with being 'crude'. Personally, I love galaxies, so I wouldn't buy a Hyperstar. The resolution just isn't there with the chips that are currently available, and if I switched to a chip that allowed the scope to be seeing limited in resolution, I'd have lost the advantages of having an uber fast system.

Keep in mind that at 100% resolution there should be no difference in signal to noise ratio, depth, or resolution, between the images produced with an 8" f/2 Hyperstar with 2 micron pixels and an 8" f/10 SCT at Cassegrain focus using a camera with 10 micron pixels.


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Phil Hosey]
      #5826026 - 04/27/13 10:46 AM

MMalik,

Read my post on f/#s.

-Rich


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: mmalik]
      #5826042 - 04/27/13 10:58 AM

OK, since hyperstar obviously does work, please explain why you think what you are espousing? Why does that sound like a good idea to you?

You seem to be completely missing the point of hyperstar. It takes a fast primary and points it straight into the camera with just enough optical power to flatten the image for a flat camera detector. In the case of a C11, you end up with a 560mm f/2 lens. The entire point of the Schmidt camera was to make that possible.

In the end, the real drawbacks are camera size (which appears to be losing relevance weekly), and back focus distance to accommodate filter wheels and such.

Otherwise, writing posts claiming something people have been successfully doing since the 1930s is impossible or infeasible seems a little peculiar on your part.

-Rich

Quote:

[quote
I just don't consider SCT a sound enough, solid enough platform to house HyperStar and the works. Personally, I would like to see HyperStar mating with CKD platform, for example, of Takahashi caliber (Mewlon 250, 300).


What would be even better... a CDK purposed/corrected for ~f/2 where one could just plug-in the camera at the secondary, without the need of intervening HyperStar. Now that will be something! ...a prime-focus HyperImaging system but without actual HyperStar correcting elements being there. I consider current HyperStar implementation an equivalent of a ‘fast’ eye-piece projection of sort. Regards




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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: BlueGrass]
      #5826043 - 04/27/13 10:59 AM

Quote:

I have a question and it may have been answered before but what about a HS capable RC? I don't see why that isn't at least possible?




Someone would first have to come up with the optics package corresponding to HS but adapted to a different primary (and no Schmidt corrector). Even if someone does that, you'd end up with something slower than a Epsilon or an RH or a Newt; nothing unique. RC scopes use slower primaries than an SCT. To address another poster's earlier questions, so do DK and Corrected DK designs.

Edited by jrcrilly (04/27/13 11:02 AM)


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: jrcrilly]
      #5826204 - 04/27/13 12:26 PM

Ah ... thanks John...

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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Starhawk]
      #5826268 - 04/27/13 12:55 PM

Do you have a raw FITS image to share?

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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Alph]
      #5826455 - 04/27/13 02:33 PM

I have RAW data. What would you like to see?

-Rich


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mmalik
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Jared]
      #5826618 - 04/27/13 04:05 PM

Quote:

The resolution just isn't there with the chips that are currently available, and if I switched to a chip that allowed the scope to be seeing limited in resolution, I'd have lost the advantages of having an uber fast system




I have said this before; couldn't agree more. Regards


Note: My high-res narrow FOV work on a slower non-HS system here...; RAWs are also there.


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: mmalik]
      #5826716 - 04/27/13 04:46 PM

Quote:

Quote:

The resolution just isn't there with the chips that are currently available, and if I switched to a chip that allowed the scope to be seeing limited in resolution, I'd have lost the advantages of having an uber fast system




I have said this before; couldn't agree more. Regards


Note: My high-res narrow FOV work on a slower non-HS system here...; RAWs are also there.




I'm going to need a bit more explanation on this. What about the Hyperstar being fast causes an issue with resolution ? It seems to me the issue Jared is talking about is in regard to image scale only. The Hyperstar isn't very good on galaxies in much the same way that my C11 at f/6.3 isn't good at wide fields.

Explain to me why a C11 Hyperstar would be worse than say, an NP101 with the same camera in regards to resolution? With the same camera they would both produce the same image scale.


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Starhawk
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: mmalik]
      #5826766 - 04/27/13 05:15 PM

You've got some pretty pictures, Mike. It seems you have been holding out on us.

Of course, that implies what this is all about is pointing out one can out-resolve a $3000 CPC 1100 11" SCT taking 30 second exposures using a $900 hyperstar system with 89 minutes of exposure with as modest a setup as a $66,700 10" TMB APO on a $27,000 AP3600.

I'm not sure this was a subtle insight any of us had missed and needed to have explained. We could have also gone down the road of pointing out how Yuri's $50,000 f/1.44 300mm astrograph would also outperform hyperstar.

-Rich


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Phil Hosey]
      #5826790 - 04/27/13 05:36 PM

Quote:

With the same camera they would both produce the same image scale.




True. Most folks tend to choose different cameras for Hyperstar than they would for other applications, though. A mono camera that would be somewhat undersampled at that focal length would be much more undersampled if replaced with a OSC camera using the same chip - and OSC cameras are the Hyperstar norm for various reasons. It costs more to own a widefield platform that doesn't care what camera one uses - but one shouldn't understate the benefits of having that flexibility. HS can be an acceptable compromise but it will always be a compromise.


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Starhawk]
      #5826847 - 04/27/13 06:05 PM

Quote:

I have RAW data. What would you like to see?

-Rich



Sure. Raw FITS images are always welcomed.


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Alph]
      #5826866 - 04/27/13 06:17 PM

MyRAW images aren't in FITS format. The camera produces 14 bit images in a proprietary format. I can export stacks as FITS, but that obviously not a raw image anymore.

-Rich


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Starhawk]
      #5826964 - 04/27/13 06:49 PM

Quote:



In the end, the real drawbacks are camera size (which appears to be losing relevance weekly), and back focus distance to accommodate filter wheels and such.

-Rich

[quote




The QSI583 with the 36mm filters installed would work quite well on a C11 or C14. It's not much different from a DSLR in size. So, there is a terrific way to do LRGB if you want to spend the bucks on the camera since the 8300 class chip works so well with short FL.

David


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: jrcrilly]
      #5827094 - 04/27/13 07:19 PM

There are a number of cameras that have come out recently that have small pixels that will get you around 1.5"/pixel and many of these are even shaped with Hyperstar in mind. There is also the filter drawer system that can be used to swap out filters making monochrome imaging with Hyperstar much more doable. I am plannig at some point to get one of the new the mono cameras with the Sony 674 or 694 chips so I can do some narrowband with the Hyperstar. Until then I'll continue to use my T2i which gives me 1.58"/pixel

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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Phil Hosey]
      #5827200 - 04/27/13 07:51 PM

Hi Phil and others.

I have the starizona filter drawer for hyperstar and the 694. The SX 894 would give you a pixel size of 1.36 The 694 is 1.67. I have never used the hyperstar or filter drawer.. lol. My 127is gives me a FOV about the same when using said h694.. aperture/speed would be the difference.... guess i'll have to do an experiment one of these days..

OSC only in hyperstar is no longer your only option.

USB wireless/bluetooth 3.0, etc dongles and sticks are becoming more widespread and faster.. Soon you'll only have that darn power wire hanging down..

Can I get some longer distance wireless power please


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: wolfman_4_ever]
      #5827306 - 04/27/13 08:46 PM

We only need to transmit that power from the edge of the OTA to the camera hanging off the Hyperstar lens. Perhaps 12 inches. If only!

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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Phil Hosey]
      #5827320 - 04/27/13 08:56 PM

Quote:

It seems to me the issue Jared is talking about is in regard to image scale only.




For a given sensor image scale would translate into resolution one is going to get. With the same aperture say C8 one is going to get less resolution with HyperStar (being wide FOV) than without HyperStar (being narrow FOV) using the same sensor. Regards


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Starhawk]
      #5827340 - 04/27/13 09:12 PM

Quote:

I'm not sure this was a subtle insight any of us had missed and needed to have explained.




Not at all Rich; was not implying that. What I have been implying, Jared I think has taken it a step further in explaining pros and cons of the HyperStar system even more eloquently. Regards

Edited by mmalik (04/27/13 09:19 PM)


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: mmalik]
      #5827361 - 04/27/13 09:34 PM

Quote:

Quote:

It seems to me the issue Jared is talking about is in regard to image scale only.




For a given sensor image scale would translate into resolution one is going to get. With the same aperture say C8 one is going to get less resolution with HyperStar (being wide FOV) than without HyperStar (being narrow FOV) using the same sensor. Regards




Yes, I know that, but you seem to imply that there is something wrong with Hyperstar being fast other than the affect it has on the focal length. Unless that is what you meant all along in which case it is obvious. But a Hyperstar C11 at 560mm is basically the same as an NP101 (540mm) as far as image scale with the same sensor, but the Hyperstar is faster.

I guess I still don't quite understand the point you are trying to make. If all you are saying is that because the focal length of an f/2 Hyperstar system is short compared to a C8 at f/10 or f/7, then yes, this is purely a function of image scale and image scale affects resolution, but being 560mm is nothing unique to Hyperstar, there are plenty of other optical configurations that would put one in that focal length range.


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mmalik
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Phil Hosey]
      #5827399 - 04/27/13 10:11 PM

Quote:

I guess I still don't quite understand the point you are trying to make.




Besides my main reservation HyperStar being on obstructed SCT/'not so solidly put together platform', I guess another way of looking at it would be one taking casual, less resolved pics in lesser amount of time on HyperStar than one taking sophisticated, more resolved pics in bit more time on unobstructed refractors. Regards


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: mmalik]
      #5827417 - 04/27/13 10:21 PM

Quote:

Besides my main reservation HyperStar being on obstructed SCT/'not so solidly put together platform', I guess another way of looking at it would be one taking casual, less resolved pics in lesser amount of time on HyperStar than one taking sophisticated, more resolved pics in bit more time on unobstructed refractors. Regards




So you don't approve of the Riccardi-Honders or Epsilon either? I've never heard them relegated to casual use before.


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: jrcrilly]
      #5827489 - 04/27/13 11:24 PM

Five pages of facts and theory demonstrating the ingenuity and facility of the HS platform and refuting the unfounded biases of the original poster. And it turns out he just doesn't like it because it's "casual."

To quote the 21st Century philosopher Katt Williams, "Haters gonna hate. It's what they do."


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: milby]
      #5827689 - 04/28/13 02:26 AM

Milby, I think you've got it. It's pretty clear the arc in tech development favors this system. And that annoys some people for specific reasons they don't want to voice. So, here we are with a thread with the final complaint boiling down to, "I just don't like it."

Sounds like the time has come to wrap it up if you ask me.

-Rich


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Phil Hosey
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: milby]
      #5827721 - 04/28/13 03:08 AM

Quote:

Five pages of facts and theory demonstrating the ingenuity and facility of the HS platform and refuting the unfounded biases of the original poster. And it turns out he just doesn't like it because it's "casual."

To quote the 21st Century philosopher Katt Williams, "Haters gonna hate. It's what they do."




Just for the record, I'm the original poster. I like SCTs and I like Hyperstar. Oh yea, and sometimes I like to be casual. I don't have any unfounded biases for or against it. Oh wait, maybe I do.. I just like it. I think you may be referring to the one who prompted me to start this thread in the first place.


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Phil Hosey]
      #5827754 - 04/28/13 04:41 AM

This has been a great discussion I think; I am sure there is lot for everyone to take away from this. I surely feel more informed than before about HyperStar and it's capabilities. Thanks to all who contributed, especially Phil for starting the discussion. Regards

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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: mmalik]
      #5827902 - 04/28/13 08:53 AM

I love my Hyperstar "crude" or not.

The End.


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: telfish]
      #5827947 - 04/28/13 09:24 AM

Sorry, Phil. I was, indeed, referring to the author of the "casual" comment.

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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: milby]
      #5828044 - 04/28/13 10:40 AM

Seriously Mike, with a rig at the level you're using, you should just get a hyperstar SCT and play with it then draw your own conclusions.

What's completely missing from this discussion is what it's like to use hyperstar in practice. You go out, get aligned, and then swap the secondary for hyperstar and hook up the camera. After that, the biggest problem is coming up with more objects to photograph and choosing camera orientations for the image capture. I

t's just a radically different experience from setting up an autoguider and spending several nights working on just one object.

-Rich


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Starhawk]
      #5828103 - 04/28/13 11:09 AM

It's also possible to align using the Hyperstar.

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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: milby]
      #5828213 - 04/28/13 12:08 PM

This is true. Especially in the case of a permanent mount, there's little reason to be setting up and taking down a hyperstar system. Come to think of it, that's what what the ISS installation is like.

-Rich


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: mmalik]
      #5828293 - 04/28/13 01:01 PM

Quote:

Quote:

I guess I still don't quite understand the point you are trying to make.




Besides my main reservation HyperStar being on obstructed SCT/'not so solidly put together platform', I guess another way of looking at it would be one taking casual, less resolved pics in lesser amount of time on HyperStar than one taking sophisticated, more resolved pics in bit more time on unobstructed refractors. Regards




Have you TRIED Hyperstar/Fastar or watched somebody using it? As I said in my post above, most of your assumptions are incorrect. If you don't want to image at this focal ratio, that's fine. It doesn't fit in with everybody's goals, but your fears and reservations are incorrect. It works just fine.


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: rmollise]
      #5829417 - 04/29/13 12:37 AM

Just ordered a Hyperstar III lens for my C11 EdgeHD. Picked up a used Starlight Xpress 26C to use with it. Do most people auto guide with Hyperstar? I will have it mounted on a AP900GTO and PEC does pretty well. I have done 10 minute unguided with a SV115T at 800mm and got nice round stars.

I figure sky glow will be quickly be my limit when imaging at my home. Hopefully will be able to go deeper when I take the rig to the GSSP in July. What's the typical exposure when doing one shot color a f/2 in a light polluted area?


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: JMW]
      #5829462 - 04/29/13 01:45 AM

You can expect to be sky limited within a minute. I've been curious myself about what can be done with really long exposures, but it would require remarkably dark skies to find out.

-Rich


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Starhawk]
      #5829517 - 04/29/13 03:15 AM

Jeff, since you live in NV, you might consider taking a spin down to Tucson to visit the Starizona store. Like most astro shops, it's much smaller than the ads might suggest -- really, just a hole in the wall. In Nov '12 I visited the store, and Dean Koenig showed me some amazing images that have been done with Hyperstar, many of them taken from the parking lot in front of the store. On Saturday evenings during good weather, he sets up scopes in front of the store for viewing and imaging. I think most of the images were stacks of dozens of 60 sec exposures with one-shot color SX cameras. The scopes are operated in alt-az configuration. The short exposures negate the effects of field rotation. I was unable to witness a viewing/imaging session, but you really should see for yourself what can be done with Hyperstar. The most memorable image Dean showed me was an image showing the Pleiades in context. It was easy to see that the Pleiades' enveloping nebulosity is just part of the IFN, not residue of the Pleiades' originating nebula. I'd never before (or since) seen such an image. Now, for my personal interest -- galaxies -- Hyperstar and one-shot color aren't the optimal tools, so it's not a set-up I own. But I was sorely tempted!

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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Calypte]
      #5829572 - 04/29/13 05:48 AM

I think a problem in this thread is that a lot of the information is old and things have improved greatly with Hyperstar III and new cameras. Unfortunately I am stuck with version II and the challenges with getting good stars across the field do in fact apply to me - but there is no upgrade path from II to III.

Some things to clarify:

Hyperstar has always been very good for narrow band work - but using one filter at a time. Even without a filter holder you can drop a 1.25" filter into the spacer that attaches the camera and do single filter Ha - and this is described in the manual. More recently Starizona started offering a small filter drawer that allows you to change them easily. Since you can capture a deep LRGB or narrow band image in much less time, it is less problematic just to expose each filter in sequence and swap them manually.

But the other big change is the compact ccd/filter wheel combos such as offered by QSI - which allow automated LRGB and multi-filter narrow band work with the larger aperture sct's. The secondary on the Edge14 is about 4.5" diameter, which is about the same size as the qsi with filter wheel - although it needs to be offset a bit. I think these are usable with the c9.25 and up.

I'm not clear about which Meade scopes can use hyperstar, but I think many of them can. There are some very good examples, including LRGB and narrowband, with both meade and celestron 14" on the web.

Regarding alignment and squaring the ccd to the image plane - hyperstar provides thumb screws with good control for adjusting it easily, whereas with a Tak Epsilon I'm not sure how this is achieved.

You definitely need to have it well focused and aligned with the image plane - but that is due to the fast f/ratio and not anything about the design.

Like anything there are good image examples on the web and some not great ones - but with Hyperstar III and large aperture I have seen many that have good stars across a wide field. The fwhm may be limited at perhaps 3" rather than 2" but again that is more due to sampling and the criticality of focus than the design itself.

Frank


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: freestar8n]
      #5829585 - 04/29/13 06:21 AM

Well, it would be a long spin. It's about 850 miles from Reno. I haven't been that far south in Arizona before.

I have seen quite a few online Hyperstar images. I realize that I will be doing wide field imaging at 560mm. I also have a AT65EDQ. Wide field is a lot of fun once you get out of town to dark skies. I have a 2 inch threaded IDAS filter that I will try out when imaging from the city.


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Phil Hosey]
      #5829592 - 04/29/13 06:43 AM

My Hyperstar and C11 should be back from Starizona later this week. I'm hoping the weather will cooperate over the next couple weeks and I can get everything tuned up and running. Then I'll likely put the Hyperstar away until after galaxy season is over. I may yet do a few wide shots of some of the larger brighter galaxies just to see how well cropping works at 1.58"/pixel that the T2i will give with Hyperstar.

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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Phil Hosey]
      #5829799 - 04/29/13 10:06 AM

I'd like to take a crack at some deep fields with it. I've been enjoying finding little background galaxies in hyperstar images of other objects.

I find its a good tool for imaging reconnaissance. The 3 degree field puts a lot of large DSOs in single field imaging range, like M31.

-Rich


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Starhawk]
      #5830154 - 04/29/13 01:06 PM

I have 3 refractors at 420, 800, and 980mm. My C11 EdgeHD can do 2800, 1920 with .7 reducer and 560 with Hyperstar. I do really wide fields with my Canon 6D and lenses. (17mm to 400mm) It's great to have a variety of focal lengths to match the objects of interest and sky conditions. I look at Hyperstar as one more tool for $900 since I already own the C11 EdgeHD. It wasn't that much more than the .7 focal reducer.

I mostly do Hydrogen Alpha using a SBIG 8300m Pro+ package at my house to avoid the light pollution. Once I get an hour out of town the Starlight Xpress 26C OSC CCD and Canon 6D become much more useful.

I am looking to buy a cheap cabin or home at a dark site about 90 minutes away possibly off the electrical grid. I would spend 3rd quarter and new moon weekends imaging there and it would be closer to some great hiking and backpacking. I want it close enough that I can still drive to work on a Monday morning. Once I retire I would spend a lot more time there. I love my Reno home and won't be selling it, but 2nd place in a black or gray light pollution zone would be fantastic.


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: JMW]
      #5830419 - 04/29/13 02:49 PM

Quote:

Well, it would be a long spin. It's about 850 miles from Reno. I haven't been that far south in Arizona before.



This is a way to see for yourself what Hyperstar does and what you need. For the money a Hypestar set-up costs, I'd think it would be worth the drive.

Edited to add: For me, any excuse to go to Tucson and southeastern AZ makes driving over there a no-brainer.

Edited by Calypte (04/29/13 02:59 PM)


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Calypte]
      #5831442 - 04/30/13 12:58 AM

DSO? How about an 11 frame mosaic of Siemeis 147 using an edge 11 with the hyperstar. 85x15min 12nm Ha frames, using a color camera to boot.

You ask and you shall receive! Just posted today!

Picture by Jeff Armstrong

Siemeis 147 Hyperstar Edge 11 85x15min Ha


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Starhawk]
      #5831599 - 04/30/13 05:39 AM

Quote:

Resolution is a function of aperture and only aperture.

...

So, the image from an AT66ED is 2.777 times brighter than the image from an SCT at the f/10 prime focus. Now, you may be wondering what gives with the radically different diameters of 4", 5", 6", 8" 10", 11" and 12" f/10 SCTs all having the same brightness coefficient, where a wee little 66mm refractor could be claimed to produce a brighter image. so, here is what you need to know: All optics with the same f/# have the same image brightness. This is why camera lenses only give their f/# range and no one really cares what the aperture diameter is except for buying filters.




I agree with the first statement but I beg to differ on the second one; while that may be true of daytime imaging it doesn't directly apply to astronomy or not in the same sense. The reason for that is because the brightness of stellar point sources in terms of total optical power is a function of absolute aperture area only (as well), independent of focal length; hence only using f/# to calculate brightness of nighttime objects is flawed a bit in my opinion. Since focal length controls the filed of view and image scale at the focal plane of a sensor, what's being lost here is resolution in the guise of quick, brighter looking images. Regards


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: mmalik]
      #5832144 - 04/30/13 12:18 PM

Can I play too..
This image alone was worth the price of admission for me - CPC1100, Canon T3, Hyperstar 3 - 30X20" frames.


This system has allowed me to do AP when I never thought I would be able to afford to do so!


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Escher]
      #5832185 - 04/30/13 12:31 PM

20 second frames! Pretty easy to get 30 of them when they are that short. That should be doable without auto guiding on my AP900GTO. Looking forward to using Hyperstar III on a C11 EdgeHD soon.

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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: JMW]
      #5832495 - 04/30/13 02:39 PM

Thats the whole point - its fast enough that tracking error or instability in the mount doesn't come into play..

Seems like a game changer in my book...

Maybe that's why some folks don't like it... Makes it almost too easy.


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: mmalik]
      #5832640 - 04/30/13 03:53 PM

Mike,

I'm sorry, but you are completely and totally off on this. Resolution is aperture, brightness is f/#. I think what you are struggling with is the concept of intantaneous field of view (IFOV), the angular extent of the sky presented to any given pixel on the camera. As you know, no telescope presents stars as pinpoints on the detector; instead you get an airy disk with some diffraction pattern around it. Now, at high magnifications, you spread this out on a bunch of pixels, and at low magnifications you focus them down on fewer ones. Hence, f/# translates as the flux of light presented to any one given pixel. Ergo, short f/# telescopes can detect dimmer objects with a given exposure.

Really- there is a vast amount of data on line. Don't take my word for it- look it up. And seriously, if you're out using a $100k rig, I can't imagine a hyperstar set would break you. If nothing else, it would be convenient reconnaisance for giving you a context frame to determine what you would like to image in a slower system or not.

-Rich

Quote:

Quote:

Resolution is a function of aperture and only aperture.

...

So, the image from an AT66ED is 2.777 times brighter than the image from an SCT at the f/10 prime focus. Now, you may be wondering what gives with the radically different diameters of 4", 5", 6", 8" 10", 11" and 12" f/10 SCTs all having the same brightness coefficient, where a wee little 66mm refractor could be claimed to produce a brighter image. so, here is what you need to know: All optics with the same f/# have the same image brightness. This is why camera lenses only give their f/# range and no one really cares what the aperture diameter is except for buying filters.




I agree with the first statement but I beg to differ on the second one; while that may be true of daytime imaging it doesn't directly apply to astronomy or not in the same sense. The reason for that is because the brightness of stellar point sources in terms of total optical power is a function of absolute aperture area only (as well), independent of focal length; hence only using f/# to calculate brightness of nighttime objects is flawed a bit in my opinion. Since focal length controls the filed of view and image scale at the focal plane of a sensor, what's being lost here is resolution in the guise of quick, brighter looking images. Regards




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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: mmalik]
      #5832703 - 04/30/13 04:28 PM

Quote:

Crude is a harsh word but I can't think of a better word for HyperStar; I am not against the creative design of HyperStar per se but I have my concerns about technical and mechanical validity of such a design (i.e., in conjunction with SCT's).

Here are some thoughts where I am coming from:

•SCTs inherently are herky-jerky design (here we go again with another not so optimal word) from collimation to mirror flop to focusers, etc.

•Corrector plate is not a rigid structure in itself and was originally designed to house just the light weight secondary

•HyperStar's fit, i.e., misfit, within the corrector plate gets mentioned quite often; stressing/flexing imparted by HyperStar is another cause for concern

•Nothing against Starizona, but I have my doubts about Starizona's HyperStar design, workmanship, & glass quality... expertise (e.g., consider a “hypothetical” HyperStar offering form Takahashi on top of a corrected Mewlon for a "hypothetical" comparison)

•HyperStar is limited to Celestron ONLY if I understand it correctly; not an SCT-wide acceptance as far as I know (in other word a proprietary offering, not an industry standard)

•Obstructed design of SCT further gets compromised by cumbersome and further obstructing imaging devices used with HyperStar

•Spiking/obstruction caused by traversing connections

•Rigidity of other designs, e.g., refractors, is just not possible in SCTs and HyperStar makes it even less rigid and more prone to stressing built-in tolerances of the SCT system

•Fastness or short circuiting of optical path ramifications of HyperStar are whole another subject that has been discussed at length in another thread...

•Uncorrected optics/folded design of SCTs


I could go on but I think you get the idea... what I am trying to get at is that we have not so optimal/rigid original design of SCT that gets further compromised by HyperStar and that's what makes it NOT so solid and/or sophisticated. HyperStar may suit video or casual still astro imagery, but high quality/high resolution still astro photography remains the domain of un-obstructed and corrected optics. Regards




Sounds like a Refractor Snob Trolling around trying to start trouble.
Too bad he is wrong on nearly if not every point...
Refractors are great! those little Fracters' make a wonderful finder on a 25" Dob..


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Starhawk]
      #5832831 - 04/30/13 05:33 PM

Quote:

Now, at high magnifications, you spread this out on a bunch of pixels, and at low magnifications you focus them down on fewer ones. Hence, f/# translates as the flux of light presented to any one given pixel.




No, the star flux per pixel has nothing to do with f/#. The star flux presented to any one given pixel depends on the aperture, and the star linear size in pixels.
Star Linear Size = (Star Angular Size * Focal Length)/206265 [mm]
Star Angular Size depends on astronomical seeing.


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Alph]
      #5833126 - 04/30/13 08:10 PM

Try again, Alph. If this were true, all you'd ever need is a 60mm department store refractor with its 525X barlow.

-Rich


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Starhawk]
      #5833225 - 04/30/13 09:14 PM

Quote:

Try again, Alph. If this were true, all you'd ever need is a 60mm department store refractor with its 525X barlow.

-Rich



What are you referring to? What's not true? Spell it out.


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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Alph]
      #5833457 - 04/30/13 11:32 PM

This is too much fun! Everyone has their own version of optics!

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Starhawk
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: milby]
      #5833554 - 05/01/13 01:31 AM

Seriously. Physics 1, anyone?

-Rich


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Starhawk
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Starhawk]
      #5833563 - 05/01/13 01:44 AM

Ok, I'll explain- look at a space photo with stars. Notice the stars are never single pixels unless photographed at the very smallest scales. e.g. The stars are are of finite size in the image. When photographed the image of the star is energy coming through the optical system and being imaged on the detector in a finite area. That image scale is a function of the focal length. The image present is a function of the area of the front end, which is where the f/#^2 comes in. That's why the 60" scope on mt Lemmon images 22nd magnitude asteroids in 10 second exposures. Of course, galaxies are overexposed blobs in those photos.

Dunno where you came up with that business about all telescopes producing stellar images of the same brightness. That's a new one.

-Rich


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freestar8n
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Starhawk]
      #5833610 - 05/01/13 03:00 AM

There are two distinct regimes - diffraction limited and seeing limited.

For short exposures (e.g. video) under good skies, the *linear* size of a star image can be diffraction limited and its size depends only on f-number. Since the light gathered goes as D^2, the irradiance in that star disk goes as D^2/f#^2 - or as D^4/f^2. This gives a huge reward to large D and small f - which is exactly what hyperstar provides. So for things like video occultation work - for which I have often used Hyperstar - it is great.

On the other hand, long exposure deep sky imaging tends to be seeing limited. In that case, the stars are no different from small nebulae - i.e. they behave as extended objects (tiny disks in the sky like a planetary nebula). Extended objects such as nebulae behave no differently from daytime objects - and the irradiance at the detector will only depend on f#. Again - that favors hyperstar. The total light gathered from the object - if it is contained in the field - goes as D^2 independent of f#, however.

Resolution is a totally different matter and depends on focal length and pixel size - assuming the image is seeing limited. But the above description is independent of pixel size and describes irradiance in the image plane - independent of whatever detector you put there.

Frank


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JoeR
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: freestar8n]
      #5833959 - 05/01/13 09:50 AM

Whether it is crude or not is irrelevant to me. It's just my personal leisure hobby I'm not seeking to get published or win any imaging awards. I just want some decent DSO images for my personal gallery. I sell some prints online and at an observatory gift shop but that's the limit of it. The speed & ease of use is what appeals to me allowing plenty of time for visual observations in the same evening. I do wish I had a longer f/l at times to get better resolution for galaxies. I compensate for it by pairing up galaxies in wide group shots when I can, which is fairly easy to do this time of year.

The concept can't be all that crude if the Discovery Channel Telescope implemented its own version of the Hyperstar for f/2.3 2° FOV wide imaging.


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Starhawk
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: JoeR]
      #5833982 - 05/01/13 10:05 AM

I think the comment may come from a poster who is annoyed by how a $4k hyperstar setup is doing in 30 seconds what he needs 89 minutes to to with $100k of equipment. Instead of trying to spread sour grapes around, it would be more constructive to adopt hyperstar as another tool. So, for example, after making a hyperstar context image, specific objects could be enhanced with longer focal length images, which could be luminance only, for example.

Anyway, I liked getting to see what some others are doing with hyperstar. Thank you for posting links and images.

-Rich


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JMW
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Starhawk]
      #5834872 - 05/01/13 05:39 PM

My OSC CCD and Hyperstar III are do to arrive on Friday. Hopefully I will be able to enjoy some 'crude' imaging this weekend on my C11 EdgeHD.

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Phil Hosey
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: JMW]
      #5834998 - 05/01/13 06:48 PM

Quote:

My OSC CCD and Hyperstar III are do to arrive on Friday. Hopefully I will be able to enjoy some 'crude' imaging this weekend on my C11 EdgeHD.




My C-11 and Hyperstar 3 just came home from Starizona today, but of course there's a week's worth of clouds and rain forcast so it's gonna be a while before I can test it out.


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JMW
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Phil Hosey]
      #5837548 - 05/03/13 01:15 AM

The forecast is clear Friday night. I am scheduled to do a couple of hours of public astronomy but I may start playing with it at about 11PM. Saturday it will cloud up.

I just looked at the clear sky clocks. I should be staying home from work tomorrow. It looks like from 1 to 4 AM the forecast is dark blue for cloud cover, transparency AND seeing. I almost never see seeing forecast looking this good.


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Starhawk
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: JMW]
      #5840167 - 05/04/13 01:59 PM

Usually those are pretty accurate. If you have power to run a monitor, you can secretly get your personal use images and the peeps at the star party will think the previews popping up are for their benefit...

-Rich


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JMW
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Starhawk]
      #5840720 - 05/04/13 08:54 PM

Well, I was too tired after getting home at 11:30 last night to try out the Hyperstar system. I was doing a few hours of volunteer astronomy. Had a good crowd and pretty good skies.

I got the Hyperstar III lens and Starlight Xpress M26C camera installed. I tried installing the M26C software on Windows 7 and the install disk didn't have 64 bit versions. I booted back to OSX Mountain Lion and Nebulosity 3 saw the camera without installing any special drivers. I was able to focus some far away trees in the daylight so I know the camera is working fine. Thunderstorm rolled in and I rolled the shed back over the pier.

The SXVR-M26C is a good match size wise for Hyperstar on my C11 EdgeHD. The camera is smaller than the diameter of the Hyperstar base so I should only have to deal with USB and power cable diffraction spikes. Should be only partly cloudy by 9PM so I hope to do some test sucker hole imaging.


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milby
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: JMW]
      #5840757 - 05/04/13 09:18 PM

If you place something linear orthogonal to the cables ( I use pieces of plastic cable ties) the diffraction spikes will at least be symmetric, like Images from Newtonians

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Starhawk
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: milby]
      #5840952 - 05/04/13 11:52 PM

Just move the cables around. I put velcro stickers on the front so I could move cables around to my liking. With a small camera, the cables are the only pattern maker. I'm playing with putting some cleats at the top and sides to attach to since the HDMI cable can pull a bit.

-Rich


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JMW
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: milby]
      #5841025 - 05/05/13 01:11 AM

Got it. power and USB opposite and a couple of matching wires to form a X from the camera to the edge of the scope.

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jrcrillyAdministrator
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: JMW]
      #5841037 - 05/05/13 01:20 AM

Quote:

Got it. power and USB opposite and a couple of matching wires to form a X from the camera to the edge of the scope.




Wouldn't need an "X"; power and USB 90 degrees apart will yield a Newt-looking set of spikes.


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JMW
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: jrcrilly]
      #5841040 - 05/05/13 01:25 AM

OK. Well that sounds simpler.

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Starhawk
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: JMW]
      #5841055 - 05/05/13 01:54 AM

Yes- that's all you need to do. The reason I have a lot of sticky spots is so I can control wire drape no matter where the mount points or what the clocking is on the camera for the object.

-Rich


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milby
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Starhawk]
      #5841252 - 05/05/13 08:21 AM Attachment (8 downloads)

Just my own experience but when I've just placed the cables at 90 degrees the diffraction patterns are asymmetric. Dummy cables in an X configuration gives nice star spikes, e.g.,

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JMW
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: milby]
      #5841521 - 05/05/13 11:54 AM

I was think about creating a supporting ring the sits just beyond the end of my camera. It would have to be slight further out than the USB cable at the end of the camera. I want to be able to support my Flatman panel and my focus mask. It would also allow my to create an X shaped rigid metal pattern crossing from 4 equally space points on the ring. The USB and power cables would run parallel on top of the metal supports so the diffraction pattern would be just like a newtonian. My dew shield could wrap around the whole setup and I could cap the end of the dew shield as a dust cover and leave the Hyperstar and camera on the C11 EdgeHD and not have to worry about dust accumulation on the corrector plate. The whole rig is on my AP900GTO so I wouldn't have to worry about the added weight. Do you think that those aluminum dew shields are rigid enough to support a Flatman panel on the end when the scope is pointed straight up shooting flats?

While I am imagining this setup, I could integrate a maglev fan on the outside of the ring to blow fresh air on my imaging camera.


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JMW
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: JMW]
      #5841545 - 05/05/13 12:11 PM

I see Astrozap sells an aluminum dew shield with notches for routing the cables. I will also buy the end cap so the shield and cap can stay on when the scope is parked.

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JMW
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: JMW]
      #5841566 - 05/05/13 12:24 PM

Just bought the Astrozap aluminum dew shield, dust cap and 2 inch Ha filter.

It's great when someone sells something that matches my imagined great idea.


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Starhawk
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: JMW]
      #5841677 - 05/05/13 01:24 PM

The 60" scope on mount Lemmon has something a little like that, but it's actually designed to defeat diffraction spikes. In that case, the 4-armed spider is supporting the lens set and camera, and has the cables integrated into it. The tops of the vanes have flat plates which are scalloped by three repeating patterns of 90 degree arcs. So, the four vanes together don't show up in the images at all. I'll have to see if I have a photo. In my case, I'm stuck with a quadrilateral pattern of some sort from the camera body.

-Rich


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freestar8n
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: Starhawk]
      #5841710 - 05/05/13 01:36 PM

If you don't like the diffraction pattern due to the camera body, you can make a circular mask that covers it and that should make the spikes more normal looking. This would incur a small loss of light but might be worth it.

To me, getting good looking stars is a challenge of hyperstar - but I see many people doing it well.

Frank


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milby
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: freestar8n]
      #5841758 - 05/05/13 02:12 PM

I'd be interested in your efforts with the Flatman, Jeff. I use an EL panel for flats right now with no complaints (perch it on the dew shield) but it'd be nice to do it automatically.

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JMW
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Re: Why do some consider Hyperstar a 'crude' platform? new [Re: milby]
      #5841975 - 05/05/13 04:25 PM

No it will be manual. It a 12 inch diameter panel. I previously just set it on the front of my scope pointing straight up. It will now sit on my dew shield when straight up. I may have a couple of 2 inch velcro to secure it. My observatory is a roll away shed. If it was a roll off roof I would consider having the panel mounted on a wall so the scope in park position would look directly at it for flats.

My camera, SVXR-M26C, is a small cylinder that doesn't block the light path at all. I bought it specifically for Hyperstar. My other camera is the SBIG STT-8300m Pro+ package. Way to big for Hyperstar.


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