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The end of OAG?

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#26 vpcirc  Happy Birthday!

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Posted 19 October 2013 - 01:35 PM

IF you like OAG that's great Dave, I'm not bashing it, but I can tell you some of the best imagers at AIC I spoke to, would prefer not to deal with rotator other than when they want to use it. Of course, as I witnessed with Adam Block, they all take matching flats on a nightly basis, for illumination reasons because you are correct, the donuts aren't that much of an issue. They must do it on both sides of the meridian keep track if the shot was to the east or to the west. Mike Rice said if this works as advertised it's a godsend. At this point they're only getting ready to release for SCT owners, which SBIG said needed it more than anyone. I don't think I've seen a rotator option for a Celestron Edge, but they worked with Planewave and got all their specs on each OTA and hopefully will be rolling it out before mine is built. I cannot speak from experience, only trust Mr. Rice and others are telling me from their thoughts. I don't think this product is geared towards large RCOS owners, and would likely not be available anyway.

#27 Peter in Reno

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Posted 19 October 2013 - 04:43 PM

+1 for OAG.

For the last few years imaging C-8 at 2000mm focal length, not ONCE I had to rotate OAG to find guide stars. No rotator is needed for me. Even after Meridian flipping, guide stars are always available in OAG's guide port. All is needed is a high sensitivity guide camera like Lodestar or ST-i and at least one usable guide star is always available especially in high light pollution area where I live. If you have an excellent mount, then increase guide exposure not only to brighten the guide stars but also to increase SNR.

OAG is getting extremely popular and there are many reports of people struggling to fix guide scope to main scope flexure issues have switched to OAG and swore to never go back to guide scope like myself. Once you get the hang of operating OAG, it's just as easy as guide scope. Another big plus for OAG is saving weight, easier balance and better ergonomics by eliminating guide scope.

I always take flats after each imaging session even if I didn't change camera's orientation. Better safe than sorry. You never know whether dust moved or added on CCD window or filters. It's so easy and quick to take flats. Flat is probably the most critical part of calibration with lights.

I am replacing C-8 with TEC 140 F/7 APO and I will still use OAG. It will be even easier to find guide stars due to shorter focal length or wider FOV.

Peter

#28 vpcirc  Happy Birthday!

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Posted 19 October 2013 - 05:25 PM

I'm sure SBIG hasn't done their research and has wasted years and 1000's on a problem that doesn't need to be fixed. Sorry I bothered to share it since it's pointless and OAG is the perfect answer for Sct's. I'll write the president of SBIG and let him know how foolish he's being! :foreheadslap: :foreheadslap:

#29 Peter in Reno

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Posted 19 October 2013 - 06:24 PM

You were the one started the argument in your original post:

By eliminating mirror issues, this seems like very promising new tech to end the pain of OAG and rotators for reflector systems.


Some of us are simply saying that operating OAG is NOT a P.I.T.A. to operate thanks to today's technology like high sensitivity cameras. Also I never need to use rotators as well.

If you had not mentioned the negatives about OAG, then I would kept it to myself and left this thread alone.

Peter

#30 vpcirc  Happy Birthday!

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Posted 19 October 2013 - 06:30 PM

The post was informational and believe it or not for some people it is a problem. It's amazing how some people can't let others look at what's being talked about without immediately saying its wrong. I'm sure the engineers at SBIG know what they're talking about, far more than anyone posting on CN.

#31 SL63 AMG

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Posted 19 October 2013 - 06:47 PM

I'm sure SBIG hasn't done their research and has wasted years and 1000's on a problem that doesn't need to be fixed. Sorry I bothered to share it since it's pointless and OAG is the perfect answer for Sct's. I'll write the president of SBIG and let him know how foolish he's being! :foreheadslap: :foreheadslap:


Mike,

I find it interesting that you are always "quoting" the best imagers and experts in the industry, but I have never once seen any of these poeple post themselves and back up your claims.

If you want to be an advocate for new products, fine, but at least try using them yourself first before making posts that are anectdotal at their core.

I don't think anyone has issue with you being the first to report a new product, it's just a little annoying when you make claims about a products fitness for merchantibility without having ever even tried it first.

If SBIG thinks this guider is going to replace OAG's in mass quantity, I think they are in for a wakeup call.

I tried guiding my 2857mm RCOS using my ST402ME on both a 250mm FL VarioFinder and a 650mm StellarVue SVRT 90mm Raptor and I can assure you that neither performed anywhere close to using the ST402ME or ST-i with my MMOAG at 2857mm FL.

Their system may work well with short focal length guiding but I don't see how it could become a feasible replacement for long focal length OAG guiding.

#32 vpcirc  Happy Birthday!

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Posted 19 October 2013 - 06:58 PM

Dave that's because most of them are in a private google group that's invitation only. They don't waste their time getting involved in silly pointless discussions on here like I do. Also, this system is not proven by any means. I saw the demo for it, I'm not advocating a brand.

#33 Raginar

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Posted 19 October 2013 - 07:27 PM

Sorry everyone is attacking you, Mike. I think it's neat and if it gives us a new tool to work with, that'll be great.

Don't sweat it :)

#34 SL63 AMG

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Posted 19 October 2013 - 09:31 PM

Sorry everyone is attacking you, Mike.


I dont get it. :confused:

Mike reports a new product. :cool:

Mike titles the product with an unlikely conclusion. :shocked:

Mike then makes anecdotal statements about the likelyhood of the products performance and impact on competitive products though this product has not yet been released and he has never used it. :question:

Mike repeatedly claims he is quoting well known people none of whom have ever publicly back up what he says. :shameonyou:

People refute Mikes claims and back it up with facts. :graduate:

You interpret it as a personal attack on Mike. :getem:

Perhaps Mike might consider evaluating his repeated "name dropping" anecdotal statements about things for which he has no personal experience and simply stick to the facts, then there will be no misperception of attacking him personally rather than his statements. Instead, we can simply discuss the merits of the information and products he wishes to share with us.

DISCLAIMER: This is not a personal attack on Mike.

#35 vpcirc  Happy Birthday!

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Posted 20 October 2013 - 03:16 AM

Dave there's a reason there's a question mark in the title. I was trying to share an item I saw at AIC that others might be interested in, as not everyone is as lucky as I to attend. I ask the questions of those who are far smarter than I, but they won't get dragged into stupid petty opinions from what one referred to as "armchair engineers" They gave their advice, take or leave it and do what you want.

#36 garret

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Posted 20 October 2013 - 03:18 AM

Sorry everyone is attacking you, Mike. I think it's neat and if it gives us a new tool to work with, that'll be great.



Not every optical system has enough backspace for a OAG.
I have a newton astrograph, with the canon 5 dmk2; there is zero backfocus left.
The Wyne corrector has only 58mm of backfocus.
You can not even use a SBIG STX 16803 with filterwheel.

I'm waiting for this new guiding system due to guiding troubles, but placing a led near the imager is practically impossible without drilling a hole into the focusser :confused:

Garret van der Veen

#37 freestar8n

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Posted 20 October 2013 - 03:38 AM

have a newton astrograph, with the canon 5 dmk2; there is zero backfocus left.



Hi-

Then you are definitely in the set of people who would benefit by guiding with a guidescope while avoiding flexure. You have a mirror system prone to flexure, and little backfocus.

In that case there is already a solution in the form of free software called FlexRX. It uses the Shift Guiding feature of MetaGuide to measure and compensate for motion detected in the arriving images. It is all based on free software, and it involves no hardware other than a video camera for guiding.

I am also a strong proponent of OAG and find it has little overhead in the imaging process, but I do aim for the brightest star available for guiding, and that does involve rotation on meridian flip and more flats - for best results anyway. If the OAG is far from the imaging chip, the difference in flats may be negligible.

But for certain systems such as Hyperstar and some Newtonians, OAG isn't practical and alternative solutions have uses.

I heard about this SBIG thing many years ago and expected they would face challenges getting it to work. A key issue is that it involves a moving centroid - which is unusual in autoguiding. For comet tracking MetaGuide also relies on a moving centroid - and I think it is the only software that guides with a moving centroid - and it has been doing so for many years.

Anyway - yes this device has been touted for years, and meanwhile there are already free software solutions for both flexure compensation without OAG, and comet tracking with or without OAG.

Frank

#38 Raginar

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Posted 20 October 2013 - 08:53 AM

Dave, just look at your tone in your writing. Mike obviously isn't quite as versed on all the options as you are. He thought it was neat and shared it. I agree with him, it's neat and i can't wait to see it.

Kind of falls into the ONG area. I dunno if I need to buy one, who am I kidding, I'm a noob who barely can get data let alone make a pretty picture, but it's neat to see something new.

I get it, you think there isn't a problem to solve.

#39 SL63 AMG

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Posted 20 October 2013 - 10:40 AM

Dave, just look at your tone in your writing. Mike obviously isn't quite as versed on all the options as you are. He thought it was neat and shared it. I agree with him, it's neat and i can't wait to see it.


You have hit the nail on the head.

There's no issue with him finding a product, thinking it's neat and sharing it. For that I am sure everyone is grateful, including myself.

The issue is that he doesn't just let it go at that. Instead he throws out anecdotal comments about the pain of OAG and rotating a camera, which provides a false impression to others who may find themselves in a situation where they need to have an OAG and may want to rotate their imaging camera. Mike does this often and I have decided that I'm not gong to sit back quietly and let it take place.

If that makes me unpopular in CN, so be it, but I know for a fact that I am not the only one that feels this way... I'm likely the only person that doesn't care if I'm unpopular for standing up and saying something about it.

If you think I'm wrong, click on Mike's nickname, then click on "show all user's posts", then see how many times he has been the very first response to someone's question and has provided subjective, rather than objective, responses to someones questions, many for which he has no personal experience.

I don't have issue with anyone wanting to be helpful, but I do have issue with stearing people down the wrong path when real money is involved.

Advice given hear needs to be objective, not subjective, so that people can make informative decisions about purchasing equipment to solve real issues.

#40 Alph

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Posted 20 October 2013 - 11:42 AM

Mike Rice said if this works as advertised it's a godsend.


I concur. The device takes us closer to point and shoot astrophotography. You can just slew to an object and start shooting.

#41 Peter in Reno

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Posted 20 October 2013 - 11:47 AM

Not every optical system has enough backspace for a OAG.
I have a newton astrograph, with the canon 5 dmk2; there is zero backfocus left.
The Wyne corrector has only 58mm of backfocus.
You can not even use a SBIG STX 16803 with filterwheel.

I'm waiting for this new guiding system due to guiding troubles, but placing a led near the imager is practically impossible without drilling a hole into the focusser :confused:

Garret van der Veen


Hi Garret,

QSI 683wsg with integrated filter wheel and OAG has back focus of 50mm to 53mm depending on T-thread or 2.156" adapter. Wouldn't this camera work?

Peter

#42 vpcirc  Happy Birthday!

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Posted 20 October 2013 - 12:04 PM

Garret, if I understood SBIG correctly, these have to be engineered to the OTA, so I don't know that they would sell one that had you drilling to mount it. It looks like Frank has a good solution for you. Again, at this point this has yet to be proven in the field by users so I wouldn't bet on this being your solution yet. As Rick stated, they've been working on this for a few years, so it appears to be more complicated than we know. I am not advocating the product only sharing what I saw. I hope it works as advertised.

#43 mikeschuster

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Posted 20 October 2013 - 12:12 PM

A couple of possible issues:

I believe SBIG mentioned using an IR light, which requires a filter on the main camera. If there are other telescopes nearby, it is important that any scattered IR light not affect them.

The retro-reflector mounted at the front of the tube is a source of potential flexure. So flexure remains an issue with this design.

Guide camera exposure time varies due to several factors (guide scope size, guide star magnitude, seeing conditions, etc.). Presumably an IR intensity control will also be necessary.

Thanks,
Mike

#44 orion69

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Posted 20 October 2013 - 01:02 PM

The device takes us closer to point and shoot astrophotography. You can just slew to an object and start shooting.


You can just slew to an object and start shooting only with high end mount without guiding. So, no it does not.

As mentioned before, this device could be usable if there is not enough backfocus for OAG.

#45 Wmacky

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Posted 20 October 2013 - 01:08 PM

most of them are in a private google group that's invitation only.


Well aren't they fancy....

#46 Alph

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Posted 20 October 2013 - 01:26 PM

You can just slew to an object and start shooting only with high end mount without guiding. So, no it does not.


It just happens that I own one of those mounts you are alluding to and they don't work that way. They require a lot of setup time and in the end you end up auto-guiding anyway.

#47 vpcirc  Happy Birthday!

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Posted 20 October 2013 - 01:30 PM

I think you misunderstand. They don't get into discussions about processes and procedures, they just share images. That's where they're interest lies, it's has nothing to so with being "special" Dave wanted to know why didn't chime in here. For great technical questions Ron Wodaski runs a great useful group on yahoo ccd-newastro with 4000+ members. His group is private too, but he lets folks in with a request. Most of these guys post their contact info on their web sites and gladly answer questions and help people. They do not however spend their time cruising Astro sites chiming in on every post.

#48 Hilmi

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Posted 20 October 2013 - 02:13 PM

Dave,

In response to your post on page 2 of this discussion.

Those of us with high light pollution and long f ratios do find OAG a pain to use. I have had many targets where I could not find a guide star when I used to image at f10. This is one of the reasons I moved to f8. In light polluted skies even a reasonable guide star is sometimes not very effective.

I agree that a good rotator with an OAG is an idea that appeals to me and I am in fact considering making such a purchase but I believe there is a market for those who find OAG don't work well with their setups.

Different horses for different races. Besides, an experienced company like SBIG will not spend the money researching a product if they did not feel there was a solid business case for it.

#49 SL63 AMG

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Posted 20 October 2013 - 03:30 PM

Dave wanted to know why didn't chime in here. [sic erat scriptum]


Please don't put words into my mouth. I never asked why "they" don't chime in here. I am fairly confident I already know the answer to that question.

I merely pointed out that you frequently refer to individuals and groups of individuals to back up your anectdotal comments and those referenced never say the same things as you say.

Of course you have now isolated "them" even further into this elite group of demigods that wouldn't dare mingle with us mere mortals.

I'm sure glad we have you as "their" liason.

What's most interesting about this whole thing is that we have exactly the same situation in Amateur Radio. The elitists, the liasons and the rest of us.

What an awesome society in which we live!

#50 vpcirc  Happy Birthday!

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Posted 20 October 2013 - 04:13 PM

I did anything but isolate them Dave. I learn from them because I take the time to contact and ask the questions . Like most imagers they will help anybody at any time. I don't just spout off. Almost every question asked here is one I had myself. I seek the advice from those who have paved the road before me. Don't worry Dave, there's no room to put words in your mouth, there seems to be something in the way.






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