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Old 20-06-2011, 02:33 PM
binofied
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Going from good to great images

As a number of you will have seen from my previous postings in another thread I am moving up from a ST2000 to an STL-11000 after finding the limited FOV to limiting. I have the following gear a Losmandy G11 with O-Vision worm, a 80mm WO Megrez triplet, Televue 0.8 reducer/ flattener for the WO and a Meade 10" LX200 OTA with a 0.63 reducer in a Ted Argos tube. I have a roll off roof and a very solid pier.

So my current boggle is that I don't think the Meade will cut it anymore. So the question is what direction to go in? As with everyone I want to take things to the next level, I think I take good images right now but want to take great images. So at that 1400 - 2000mm mark what OTA would work best?

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Old 20-06-2011, 03:36 PM
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How about the new GSO 12" RC f/8. They seem to be a bargain.
Paul Haese (from here) is testing one.
http://www.andrewscom.com.au/images/...c/gso-rc12.jpg
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Old 21-06-2011, 08:26 AM
Hagar (Doug)
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Hi David, not to many responses yet but here is my 2 cents worth.

To step up from a 10"eade the choises are relatively slim. Most commercially made or at least mass produced scopes in this size have their own inherrant problems which will take some work to get up to the standard you are after.

The biggest problems you seem to face are:
The weight of the outfit and the carrying capacity of your G11. Anything bigger than a 10" will most likely be to heavy for the G11.

Image circle of mass produces scopes.
Most only come with a 2" opening which is a bit small for the ST11000, particularly if you need to use a flattener or reducer.

I think your options are limitted to the standard scopes in the 10" range such as the 10" GSO RC, Deep sky instruments 10" RC (Probably your best option.) or a Meade 10" ACF.

Out of this range the DSI Rc is probably the one which is designed with a corrector which will handle the 11000 camera. Even this will be touch and go on weight and will cost significantly more than the other two. This said it should work out of the box without requiring a new focuser which both other scopes will require before they can bbe used.

Good luck.
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Old 21-06-2011, 09:00 AM
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I don't think aperture will necessarily make greater images. You'll get better resolution for sure depending on your location and seeing but it's a whole new ball game. It is likely your FOV will also be more limited by going bigger because your FL might also be longer depending on the scope. Big aperture with short FL is costly. I'm not clear on what you are trying to achieve? Wider FOV?
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Old 21-06-2011, 02:31 PM
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I don't think aperture will necessarily make greater images. You'll get better resolution for sure depending on your location and seeing but it's a whole new ball game. It is likely your FOV will also be more limited by going bigger because your FL might also be longer depending on the scope. Big aperture with short FL is costly. I'm not clear on what you are trying to achieve? Wider FOV?
I was always feeling that the small ~12x9mm chip on the ST2000 while being a truely great camera was giving me a limiting FOV. I have managed recently to liberate some money by selling my 16" Binocular telescope. This money has gone on an order for an STL-11000. So now I have a camera with a huge chip and an old SCT that won't fully illuminate it. Given this and that I currently have a mount that is limiting the weight I can carry, I was fishing to see if anyone came up with a recommendation for a perfect match and able to blow the Meade optics out of the water at the same time.

Perhaps at this stage I should simply crop the Meade images so they are OK and put money into something like the new baby Paramount, so that I can go crazy with optics at a later date?

As always tighter stars, better contrast, lack of CA leading to higher quality final images is my goal.

BTW I am more interested in Nebulas, both bright but especially dark rather than galaxies. I have little interest in planetary imaging.
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Old 21-06-2011, 03:47 PM
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I do not know what your budget is but you could look at the Planewave CDK 12.5. The weight of this might be a bit much for a G11 coming in at 22Kg. The time you add your camera ect you will be right on the limit of the G11. If you check out Planewave's website you will see a fantastic gallery of images. You will notice quite a variety of mounts and imaging techniques. I have ordered one of these after quite a long process of elimination. I looked at the Mede ACF the Celestron edge HD some RC's and other scopes but the quality of the images of the CDK seem to out shine them all. The GSO was not released at the time so I did not get to compare it against the CDK. Price is good compared to RC's but is quite a lot more than a Mede, Celestron or GSO.

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Old 22-06-2011, 08:13 AM
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Quote:
Originally Posted by binofied View Post
I was always feeling that the small ~12x9mm chip on the ST2000 while being a truely great camera was giving me a limiting FOV. I have managed recently to liberate some money by selling my 16" Binocular telescope. This money has gone on an order for an STL-11000. So now I have a camera with a huge chip and an old SCT that won't fully illuminate it. Given this and that I currently have a mount that is limiting the weight I can carry, I was fishing to see if anyone came up with a recommendation for a perfect match and able to blow the Meade optics out of the water at the same time.

Perhaps at this stage I should simply crop the Meade images so they are OK and put money into something like the new baby Paramount, so that I can go crazy with optics at a later date?

As always tighter stars, better contrast, lack of CA leading to higher quality final images is my goal.

BTW I am more interested in Nebulas, both bright but especially dark rather than galaxies. I have little interest in planetary imaging.
I understand now. If I were you I'd get a 12" F/3.6 ASA. They're beautiful scopes by the pictures I've seen posted around and in a league of their own for the money. Nothing comes close. That's the ideal rig for a widish field set-up with plenty of resolution.
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Old 22-06-2011, 09:20 PM
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Thanks for all the great replies, probably the 12.5CDK is the one that appeals most, known company, easy collimation and good quality. Read a few reviews of people having issues with the very fast ASA's as far as getting the camera square and collimation issues. Buying a Meade in NZ is ridiculous the local agents give zero backup and charge like mad for average equipment. I will never by Meade again.

As for the GSO the main negatives seem to be the focuser which is solvable and adaptors to get the CCD to flattener spacing correct and solidly mounting such a long image chain. I understand the adaptor/ extension tubes needed are not off the shelf items? Also collimation it seems may not be as easy as I thought. Solidly mounted ali dovetail plates on the Carbon fibre tube is also a complaint, again Planewave solved this by a simple slip joint, can't see why I can't. I haven't heard anyone say the GSO optics are below average?

I know I did ask about the best possible options, the question then is, can you make a cheap GSO telescope work wonders given a modest extra investment in focusers and adaptors or is just paying double the price for top quality gear the best road to travel.
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Old 23-06-2011, 08:39 AM
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Has anyone any experience with the 8" Vixen VC200L (which may be a step sideways from the Meade 10") or the Takahashi Mewlon 250?
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Old 23-06-2011, 08:45 AM
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probably the 12.5CDK is the one that appeals most, known company, easy collimation and good quality.
I have a friend who's had a 12.5" CDK for the pas 2 or 3 years. It is a small FOV. You'll fit half of M8 in your FOV so if you think your field was restrictive I wouldn't go for one of these. This is more of a galaxy hunting type of scope. I don't even know if they offer any kind of reducer.
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Old 23-06-2011, 04:57 PM
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I have a friend who's had a 12.5" CDK for the pas 2 or 3 years. It is a small FOV. You'll fit half of M8 in your FOV so if you think your field was restrictive I wouldn't go for one of these. This is more of a galaxy hunting type of scope. I don't even know if they offer any kind of reducer.
Planewave offer a .66x reducer, taking the scope from f/8 to f/5.3.

Cheers
Phil
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Old 23-06-2011, 05:18 PM
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I understand now. If I were you I'd get a 12" F/3.6 ASA. They're beautiful scopes by the pictures I've seen posted around and in a league of their own for the money. Nothing comes close. That's the ideal rig for a widish field set-up with plenty of resolution.
Gee, dunno Marc. Given they dont actually work for most ppl (ask Mike S, and MANY others), the support is crap and they cost way more than the AG12 f3.8, which actually does work (ask Mike S, and look at his pics, despite the slightly funny stars) .

The CDK does look good, would be a toss between them and AG IMO.
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Old 23-06-2011, 05:19 PM
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It is a small FOV..
umm, and what exactly is the prob with that............
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Old 23-06-2011, 05:42 PM
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Gee, dunno Marc. Given they dont actually work for most ppl (ask Mike S, and MANY others), the support is crap and they cost way more than the AG12 f3.8, which actually does work (ask Mike S, and look at his pics, despite the slightly funny stars) .

The CDK does look good, would be a toss between them and AG IMO.
Tom Davis had one and this is taken with one as well. That tops the AG12 IMHO. So they can't be all that bad. I know big Mike had issues with his and returned it. May be he got a lemmon but I don't think it's fair to generalise. I'd get one in a heartbeat.
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Old 23-06-2011, 05:50 PM
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. So they can't be all that bad. I know big Mike had issues with his and returned it. .
Ooooh, thats just the tip of a gigantic iceburg, Mikes problems were minor...............Anyway, perhaps they have things sorted now. I wouldnt trust them in a "heartbeat" going by the way they went about dealing with "issues" either, thats a whole different interesting subject itself.
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