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Why are there so many people who hates SCT´s

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#376 tim53

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Posted 26 June 2011 - 03:23 PM

Not really, Jon. Since the primary is a sphere, all you need to do is be able to adjust the secondary. More adjustments would just complicate the issue for no good reason. Ask some Blue and White C-Pacific owners.



Even if is spherical, the sphere needs to be centered. If the mirror is tilted then it is not centered.

Jon



That's why MEADE advertises with an oversize primary. It gives you some leeway there as far as I can see. But maybe I am barking u the wrong tree here.......


One of the goofiest things I've ever seen is when I tried to use my Lasermax holographic laser collimator on my C 9.25". Got a really nice pattern on the wall in front of the scope, then plunked an eyepiece in and gee-whizzed Jupiter with it. AWFUL! readjusted to get the planet as sharp as could be, and now the holographic target is off center.

I've got an off-axis 9.25", it would seem. If I ever mod this thing, one thing I'll do, in addition to adding ventilation, is fix the primary-secondary separation, add the means to collimate the primary, focuser and baffle tube, and put a crawfish focuser on the back and use extension tubes for accessories that need more out travel.

Still, I like my SCTs. I don't hate them.

-Tim.
 

#377 Mitchell Duke

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Posted 26 June 2011 - 03:25 PM

Christopher Go has made digital photos of Jupiter and Saturn that come near the detail of Hubble pictures. He uses a 14" SCT.


No he hasn't (and he uses a C11). The Hubble's resolution is infinitely superior to anything that any ground-based amateur scope has ever produced.


Infinitely superior? I don't think so. His work does all the talking. It is easy to remove frames from video where the atmosphere is interfering with resolution. I did say NEARLY and I still stand by that statement. I don't know of any other imager that has shown Saturn's ring spokes.

http://saturn.cstoneind.com/


Buddy,
You are so very wrong! Myself, and Wayne have both captured the ring spokes in numerous images. You also need to look again at the Hubble shots they should not even be compared. I think that Chris's shots are a little too noisy, and thats just a taste preference on my part. He likes upscaling, and shooting at higer focal lengths to get some of the smaller detail. I on the other hand like to get a more natural look to my shots. Make no mistake Chris is good, but have you looked at the other CNers?
 

#378 buddyjesus

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Posted 26 June 2011 - 03:37 PM

I wasn't wrong. I just didn't know that you got them also. I generally don't look at imaging discussions as I have little interest in them. I have too many other threads to read that are more relevant to me.
 

#379 David Pavlich

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Posted 26 June 2011 - 03:45 PM

[You are correct.

BUT that off-the-shelf Newt will cost Thousands and Thousands of dollars less. And if you are into visual, video, or lunar/planet imaging, the Newt with tracking and goto (like the Orion Dob/Newt) will give you the same results as the C14. The disadvantage of the newt is that it is more bulky.

New price for a C14 and Pro mount around 8-10K

New price for an Orion 14” dob/ newt $2,500

You can also find of-the-shelf solid tube Newts that cost less than a C14 OTA. If you want to to long-exposure imaging, etc.

The Newt gives you a choice of off-the-shelf optics & lower cost OR premium optics that cost more but deliver better results. The mass-produced SCT advantage and its ONLY advantage is that it is the most compact tube per-inch of aperture.
Bob


Very true, all. My reaction wasn't to the price, it was to the performance mismatch of the premium mirrored Newt to the off the sheld SC. Heck, I own a 10" Astro Tech imaging Newt. :grin: Talk about your bang for the buck!

As a former C14 owner, I know it takes a lot of mount to make it perform. And as a former off the shelf Newt owner, I know that they are a LOT less expensive. But under typical conditions, inch for inch, there is little difference in the views.

My point is that in this type of thread, somehow it's the SC that is compared to the performance of a premium scope, be it a refractor or a Newt. :grin:

David
 

#380 rmollise

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Posted 26 June 2011 - 03:50 PM


One of the goofiest things I've ever seen is when I tried to use my Lasermax holographic laser collimator on my C 9.25".


Using a Newtonian laser on an SCT is, as you discovered, a recipe for miscollimation. Cure? As the doctor said, "Well, just don't do that anymore." ;)

The alternatives:

Polaris
The Hotech CT Collimator.
 

#381 jmiele

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Posted 26 June 2011 - 04:11 PM

I can't believe it. I would never thought it possible for this thread to get off topic :) There are now 3 seperate discussion lines.
:)

I have to agree with whduke about the CN planetary photographers. Some of the best work around buy amateurs is being done here. Some from great locations, and other not so great locations.


Joe
 

#382 tim53

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Posted 26 June 2011 - 05:07 PM

Actually, I bought the lasermax to collimate my Cassegrain, since a point laser won't get you past collimating the focuser.

My Cass has adjustments for all the critical parts, because I built it that way!

-Tim.
 

#383 WayneJ

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Posted 26 June 2011 - 05:20 PM

I wasn't wrong. I just didn't know that you got them also. I generally don't look at imaging discussions as I have little interest in them. I have too many other threads to read that are more relevant to me.


You were indeed wrong.. twice now. Perhaps you should go back to whatever threads "interest" you and not simply try to increase your post count with factually inaccurate information that serves no purpose.

Go to the link you posted to confirm that Chris indeed uses a C11, then look below and see that others have also imaged spokes on Saturn's rings. The fact that you weren't aware of anyone else's images doesn't excuse that you made the statement in a manner meant to suggest that Chris was alone in this feat. Chris wasn't even FIRST at imaging spokes. Most credit Emil K. (MVZ on these forums) with that. (edit: among amateurs I should say -- a number of NASA space probes imaged the spokes from near Saturn and the HST captured them years before it was even remotely possible from ground-based systems, I think the first visual observer to report these was Stephen James O'Meara back in the '70's iirc... but I'm not 100% sure about that).

Posted Image

or how about this one I took on 12/31/10 -- over FOUR months prior to opposition? The extremely dark spoke on the left side of the image was a source of interest to the Cassini imaging team, as we'd never witnessed a spoke that dark.

Posted Image

There are a group of amateurs that works closely with various NASA/JPL researchers to combine ground-based observations (i.e., survey data) with high-resolution imagery from the Cassini satellite. SCTs may be the source of consternation and derision around these rather intellectually bankrupt fora, but the genuine contributions they make to amateur astronomy speak volumes about the value of the SCT.

Regards,

Wayne
 

#384 Jon Isaacs

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Posted 26 June 2011 - 05:23 PM

You say that the stacking gets rid of all of the optical issues? Well if thats the case why not download registax to upgrade our mass produced optics into the spectacular optics you are bragging about?



First:

Let me make it clear that I make no claims as the owning fantastic optics, just the decent optics that are well prepared and located in one of the mildest climates in the world, one where seeing is probably better than most of you experience.

Second: Optical issues includes a variety of factors, not only the telescope scope optics but the thermal issues and the seeing.

Third: When you figure out how to use Registrax at the eyepiece, I am sure that many will be very interested in knowing.

Jon
 

#385 Rick Woods

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Posted 26 June 2011 - 05:24 PM

I really dont think alot of people get that it does not matter which type of scope you have as long as the seeing is good.

I don't think a lot of people get the fact that it's Damian and Chris that are premium performers, and most of the time spent on the image is spent at the computer. These guys are just good. They're people who will excel no matter what equipment they're given. Their telescopes aren't particularly better than what any of us have. But, they are.

And, to whoever pointed out how silly it is to compare imaging to visual usage, thank you! It's like comparing your CD player to your TV. It's true - movies look a lot better when you watch them on the TV.


You know I am sure if we had the awesome seeing / dark skies that Damien, Chis, and Bird had we would all be the best imagers out there. I believe that the hard working / dedicated folkes in the Solar System Imaging forum deserve just as much credit as these guys.

Oh come on! Are you seriously suggesting that the dark skies are all there is to it? Do you deny that in any field, especially an artistic one like imaging, there are people who are just plain better at it, naturally?

Anyone who works hard at something deserves credit for it. But it's ludicrous to imply that individual talent and natural ability aren't a factor, or indeed the main factor. There's a reason Peach is regarded as highly as he is, and seeing/dark skies are only a minor part. Jimi Hendrix would still have sounded like Jimi Hendrix no matter what equipment or conditions he was handed.
 

#386 MikeBOKC

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Posted 26 June 2011 - 05:33 PM

Jon's point about eyepieces and differential magnifications a coupl of pages back are of course well taken. As I noted in my post, this was decidely NOT a scientific experiment . . . rather a series of views through two scopes on the same field at the same time, based on a prejudice that good scopes are good scopes, regardless of design, and that SCT can and do hold their own in just ab out any comparison. Which ultimately goes back to the original title of this thread and the fact, now well estabished, that design is more a matter of taste than in inherent inferiority or superiority.
 

#387 Jon Isaacs

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Posted 26 June 2011 - 05:50 PM

Jon's point about eyepieces and differential magnifications a coupl of pages back are of course well taken. As I noted in my post, this was decidely NOT a scientific experiment . . . rather a series of views through two scopes on the same field at the same time, based on a prejudice that good scopes are good scopes, regardless of design, and that SCT can and do hold their own in just ab out any comparison. Which ultimately goes back to the original title of this thread and the fact, now well estabished, that design is more a matter of taste than in inherent inferiority or superiority.


Mike:

You mentioned that it was most interesting to you because you were considering an 14 inch Dob to round out your stable. With one scope at 75x and one scope at 155x, I don't see that there are any possible conclusions...

Jon
 

#388 barasits

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Posted 26 June 2011 - 06:24 PM


Rebel Yell is better. Seriously.


Well, duh... :lol:


Jameson is triple distilled and twice as smooth as mass produced American whiskeys that are distilled only once. So under good drinking conditions, the smoothness of my glass of Jameson will outperform your rough hewn Rebel Yell. Yes, Jameson costs more, but it's made by master distillers who hand finish each bottle. It's all about performance. Wait a minute, I think I'm getting my subthreads confused. Another shot of Jameson will clear up the problem...

Geoff B.
 

#389 buddyjesus

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Posted 26 June 2011 - 06:30 PM

I did say NEARLY and I still stand by that statement. I don't know of any other imager that has shown Saturn's ring spokes.


I in no way said he was the only person ever to photo that detail. I said he was the only one I knew of. Quit lying about what I said. Go troll someone else or STFU.
 

#390 Vondragonnoggin

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Posted 26 June 2011 - 06:34 PM


Rebel Yell is better. Seriously.


Well, duh... :lol:


Jameson is triple distilled and twice as smooth as mass produced American whiskeys that are distilled only once. So under good drinking conditions, the smoothness of my glass of Jameson will outperform your rough hewn Rebel Yell. Yes, Jameson costs more, but it's made by master distillers who hand finish each bottle. It's all about performance. Wait a minute, I think I'm getting my subthreads confused. Another shot of Jameson will clear up the problem...

Geoff B.


I thought this was about SCT's? Southern Comfort Triple
 

#391 WayneJ

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Posted 26 June 2011 - 06:51 PM

I in no way said he was the only person ever to photo that detail. I said he was the only one I knew of. Quit lying about what I said. Go troll someone else or STFU.


You said Chris used a C14. He doesn't.

You said his images "nearly" show the detail of the HST. They certainly don't and anyone supporting such an absurd claim doesn't know the difference between an orbiting 2.4m multibillion dollar platform and a C11.

You said that Chris was the only imager that you were aware of had captured spokes on Saturn's rings in a manner that implied that he was alone in that. If your statement wasn't technically "wrong", it was certainly made with extraordinary ignorance and a complete disregard for the truth. Choose which one you like better.

Since you need to resort to vulgarity through acronyms, it's evident that your ignorance is all you have to rely on and refuse to admit that you were simply wrong on all counts. Feel free to explain (without profanity) how I misinterpreted your ignorance.
 

#392 TG

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Posted 26 June 2011 - 06:55 PM

You could probably get the same results with a big, long Newt...but we don't see many/any from them in the Chris Go - Damian Peach league. Why? Probably because nobody wants to hassle with a beast like that when you can do such incredible work with a "lowly" SCT



Indeed.. But Anthony "Bird" Wesley uses that F/5 and seems to do some wonderful things. Considering all the folks imaging the planets with SCTs and so few with Newtonians, one would have expected that the Jupiter impact would have been discovered with an SCT...

Jon


I highly doubt that scope design had anything to do with it. It was afterwards imaged by many SCTs so it wasn't the scope. The real factor I think was Bird's location, the land of Oz, where Jupiter was nice and high in the sky which together with local seeing conditions let him image the impact before anybody else.

Tanveer.
 

#393 buddyjesus

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Posted 26 June 2011 - 07:05 PM

I left it for idiots to imply the meaning behind what I typed. My one error was corrected already and I had no reason to correct myself after it was already done(the act of someone adding to post count with nothing to add.) I have seen side by side comparisons of his photos to those of hubble and was greatly impressed. I consider nearly to mean that 90% of what Hubble shows. I stand by my statements of his ability and quality. As for my use of a common internet acronym, go cry in a corner or DIAF. You choose.
 

#394 rmollise

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Posted 26 June 2011 - 07:10 PM

Actually, I bought the lasermax to collimate my Cassegrain, since a point laser won't get you past collimating the focuser.

My Cass has adjustments for all the critical parts, because I built it that way!

-Tim.


That's fine, but forget using your laser on an SCT. ;)
 

#395 James Paulson

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Posted 26 June 2011 - 07:42 PM

I can't believe it. I would never thought it possible for this thread to get off topic :) There are now 3 seperate discussion lines.
:)

Joe


I know, ain't it great :lol:
 

#396 David Pavlich

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Posted 26 June 2011 - 08:03 PM

[Jimi Hendrix would still have sounded like Jimi Hendrix no matter what equipment or conditions he was handed.


Sorry Rick...gotta' call you on this one. The Star Spangled Banner at Woodstock wouldn't have had the same effect had he been playing a Martin acoustical. :grin:

David
 

#397 Rick Woods

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Posted 26 June 2011 - 08:37 PM

[Jimi Hendrix would still have sounded like Jimi Hendrix no matter what equipment or conditions he was handed.


Sorry Rick...gotta' call you on this one. The Star Spangled Banner at Woodstock wouldn't have had the same effect had he been playing a Martin acoustical. :grin:

David

Don't be so sure! ;)
 

#398 Joe Bergeron

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Posted 26 June 2011 - 08:49 PM

I left it for idiots to imply the meaning behind what I typed.


I'm sorry, but you are using the word "imply" incorrectly. Please refer to my English Lessons for Amateur Astronomers, linked below. Just piling on.
 

#399 rick rian

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Posted 26 June 2011 - 08:55 PM

And we're done.

Thank you all for your contributions.
 


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