Choosing a mount, telescope, and camera for CCD imaging can be a daunting process. Here's a synopsis of the decision track for getting good results from your equipment choices.
I could go on forever, I guess, but that should be enough to shake up anyone's assumptions.
In the end, I can only say what I would do. If I had approximately a $10k budget, here's what I would do:
Those are just the obvious; there are many more such combinations that would (approximately) fit the budget. Download my CCDCalc program to experiment with different camera/telescope combinations.
I've learned over the years that if you buy quality at each key point (mount, camera, telescope) you will be happier. An all-in-one purchase like an LX200 makes sense if you are exploring, want to do as much visual as imaging, and are willing to trade time for the money saved (learning how to get the most out of the equipment, which can also be a lot of fun!). It eventually comes down to what is most important to you. I have one friend who started out with an older used C8 setup just so he could make new bearings and turn it into an imaging capable mount. He was very happy when he got to the point of taking 10-second unguided images. Another friend started out with a 16" Ritchie-Chretien, and he's happy too, even though it took him about a year to finally get everything tuned and performing well. But most folks I know who are really happy start out with good mounts, small refractors, and a modest but quality camera. That's a good neighborhood for a starter setup.
Make sure you really like, and can live in, the other neighborhoods before you buy property there.
I received this response from Mark de Regt; it raises some interesting ideas so I have added it to this page. Visit the ccd-newastro Yahoo group to see other follow-ups to these ideas.
This piece basically assumes that one has no good equipment to start with, which would most often be the case only with one who has never really spent time with a scope. I think it's a bad idea for someone with little or no experience with astronomy to plunk down up to $15,000 on equipment (unless he doesn't mind losing 30-40% of that when it turns out he's not cut out for the demands of this hobby and sells his stuff). The idea of someone who has never spent several consecutive nights gazing at the sky all night, much less dealt with the total frustrations of imaging, diving right in and spending that kind of money is hair-raising to me (unless, as I said, money is no issue).
Secondly, if the person wants to do visual work (as the guy who started this thread did), no small refractor is a good choice; my ancient, budget-priced 10" LX200 will blow the drawers off of an FSQ106 for most visual uses, costs less for scope, mount and tripod than just the OTA for an FSQ, and is much easier to use than an FSQ on a fancy GEM.
There's no question that, once one is certain, based on a decent amount of experience, that one wants to do imaging, buying a good mount is a good way to go (and, IMO, a Losmandy G-11 does not rise to that level, despite its cost). Likewise, imaging with a fine mount, an FSQ and something like an ST-2000 would be a joy, but one would also have to buy a 10" or larger catadioptric OTA in order to do visual work, if that's what one wanted.
I truly think that, for someone who has little or no history in visual astronomy, but is fascinated by it in theory and is asking about what equipment to buy for imaging and visual work, the best advice is to start relatively small, see if this is really for you, and work you way up. If they're determined to spend money, get an LX200, which is a fine optical instrument and easy to use. If they find that they are up every time there are clear skies and not too much moon, then move on the imaging equipment if you want; starting with a used ST-7E is a great way to do this. That's still less than $5000 spent, and you now have a nice scope, wedge and camera. If money is no issue, he can easily sell the LX200 and buy a fancy mount if he wants, once he is certain that he really is hooked by this hobby. Or, of course, he can get an AO-7 and get great pictures with an LX200.
There is also the issue, ignored in your piece (not criticism, since this complicates the decision tree tremendously) but quite important in real life, of what equipment to buy if you already have some decent equipment, and you want to build around that. So many people already have an LX200 or something like it, and reading your piece will convey the impression that that won't work.
- Mark de Regt, ccd-newastro group co-moderator
This is my reply to Mark's comments:
You raise some good points, Mark. I did focus on the person buying from scratch or doing a total replacement. The questions get more complicated when you have equipment, some or all of which you want to use for imaging. Here are some guidelines for someone who already has some equipment and wants to move into CCD imaging:
I like small refractors myself. My Sky90 is one of my favorite visual instruments; binoculars are my other favorite. I agree that additional aperture adds things you simply cannot see in small scopes, but the small scopes are just so darn portable and easy to get set up that I favor them.
I like your description of how a mixed visual/imaging astronomer should assess their options. We cannot overemphasize how much value you get out of an AO-7. It can greatly expand the capabilities of one's setup because it takes over fine guiding from the mount, making the mount a much smaller factor in the equation. I still prefer a high-quality mount because the AO-7 does have a few limitations, the main one being it really needs very bright guide stars and they are often in short supply outside the Milky Way.
I can validate your last point: making use of existing equipment for imaging can save you a ton of money and is often a good choice. It does complicate things (I hope the guidelines above will be of at least some help). I would encourage anyone who has equipment to drop a line here about it to get some feedback on whether (and how) it can be used effectively for CCD imaging.
Here's another interesting post from that thread, from Peter Erdman. Peter makes a strong case for the LX200 approach, with some good logic that should help those interested in the LX200 evaluate it accurately.
You won't get several people to agree on some "perfect" solution because there isn't one. Each solution satisfies an individual's priorities, and each person is somewhat different. Those who are expert are basically advising you on what they would do if they started all over again, but presumably retained their present knowledge.
For you, since you have professed a continued interest in visual observing, want a telescope of smaller bulk than a Newtonian, don't wish to concentrate on the planets or solar observing, have some interest in CCD imaging, and some experience in film photography--the answer is simple.
Get the roughly 12" SCT you have suggested, with its entire mount. Also buy an SBIG ST-7 and one of the various reducers available for this size camera (I would suggest the Optec 0.5). Now you have a decent visual mount, good GOTO, and a nice camera with self-guiding to start trying CCD imaging (with a wedge). You can spend a lot of time before you exceed this system's capabilities, and during that time you decide if this particular bit of insanity is what you wish to further commit to.
If the answer is yes, then you have lost essentially nothing. The SCT mount can be enhanced with an AO-7, or the OTA can be moved to a more expensive mount (about $5K for a Losmandy Titan), the ST-7 can be used for a guiding camera if you wish to upgrade to whatever larger camera is most cost effective at the time (this may be a year or two you realize?), the SCT mount can be used as a very widefield camera imaging platform. You have lost nothing, even if you choose not to sell any of the components.
The SCTs are so cost effective (mount and all) that they only get ignored by those who have already spent considerable time with them, and are willing (and financially able) to move to something else, or by those whose main interest is planetary or solar observing (somewhat specialized). On the other hand, some of the finest planetary images I have ever seen have been taken with a Meade 12" SCT.
By the time you have all this working you won't need to solicit anyone else's opinion on what equipment to buy--you will be quite able to decide on your own, based on your own priorities.
- Peter Erdman
Copyright © 2000,2001 by Ron Wodaski. All rights reserved. Material may not be used without permission. If you provide a link to these pages, please send me an email message at firstname.lastname@example.org about the link, and I will add a reciprocal link to my site.