The New CCD Astronomy - 488 pages, 8.5x11" $49.95 ISBN: 0-9711237-0-5

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.

  • The mount comes first. Everything you do depends on the mount, so the quality and weight capacity of the mount are key determining factors in your success. And ultimately it is the quality of the mount that matters; a mount with a large capacity but poor tracking and guide performance will be limited to smaller scopes with short focal lengths. I'd rather have a high-end mount and an inexpensive scope and camera than any other combination of those three things.
  • Convenience is a key factor. Many folks who get into CCD imaging underestimate how much work is required. If you have plenty of time, are not fazed by a long, tough learning curve, then a larger aperture and a long focal length may be OK for getting started. But make no mistake: if you start with a long focal length, you'll have plenty of work to do and a lot to learn. The reason is simple. If you start with a long focal length, all of the variables have to be mastered (tracking, guiding, balancing, rebalancing for specific situations, PEC, tuning the mount, reworking the mount as required, and on and on an on.) For some, this is fun. For others, this is nothing but frustration. By starting with a short focal length, you remove a number of variables and you can just enjoy yourself. [And we are still just talking about the mount's capabilities! Convenience also applies to the camera; see below.] Unless you are really certain that you would enjoy a sink or swim approach to imaging, start with a good mount and a short focal length.
  • Optimizing every component takes a big budget. If you have a fixed budget, then put your money where the quality matters most, and never settle for a single component that falls below the quality minimums.
  • It is important to understand the trade-offs. It is just about impossible to master all of the trade-offs when you are first buying equipment. Experience is what teaches you about the trade-offs in this hobby. You can ask questions all day, every day, for a month, and even if you get good answers you won't have a context to make sense out of those answers. Buying your first imaging setup is like a first date: no matter how many people you ask, it will eventually come down to your own personal preferences. What you like may be completely different from what the next person likes. And you probably won't even know what you like until you get some imaging under your belt. The solution here is to start simple and stay flexible. Buy used if you are comfortable with that approach, and buy stuff that will hold value - it will hold value because many people value that item, which means in turn it's probably a pretty good item overall. And keep in mind that there will be trade-offs where you didn't anticipate them. You might, for example, find it difficult to appreciate the trade-offs between, say, a small refractor and a large SCT until you have some time with both under your belt. When I just want to have fun imaging, I set up a small refractor and I'm a kid again. When I want to work, and achieve something special, I set up the large scope and sweat buckets getting everything just so. Both approaches are valid, both are enjoyable, but the experiences are totally different.
  • If you are a visual astronomer, set aside your preconceptions. What you know about visual astronomy can often steer you in the wrong direction when it comes to imaging. Something as simple as the ability to change eyepieces disappears when you move to imaging. Other than using reducers (which have sometimes huge trade-offs), you are locking yourself into a specific field of view when you marry telescope and camera. There will be other surprises as well; set aside your assumptions about what should happen and just listen and learn. It's a very different experience, and I can't tell you how many times assumptions fell flat for my students. (As an aside, beware of "conventional wisdom." There are a lot of outdated ideas floating around that actually have no basis in fact. We spend a lot of time here in the Yahoo group for the book debunking old wives' tales. Visit the group to learn more.)
  • Choosing a camera isn't a simple choice - you have to factor in the abilities of your mount and telescope in order to choose a camera effectively. And you need to choose between blooming (high QE for going deep or doing science) and non-blooming (convenient, a pleasure to use, significantly less sensitive) cameras. Granted, camera choice isn't critical, but it is important. Everything from pixel size to the manufacturer's supplied software and support plays a role in making a good decision.

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:

  • I'd start with a quality mount. In fact, I would overspend on the mount because you can never have too much mount. I would look at a Tak mount, or a Mountain MI-250, or maybe a used Astro-Physics mount. The list of mounts that are desirable for imaging is a very short list. Let's assume I get myself a Mountain MI-250. That means I'm spending $6,000 on the mount alone! But I've got a mount that will handle various small to medium size telescopes, and a few of the fairly large ones, for many years to come. Since learning and understanding your mount is a key component of success, as I use this mount over the years I will learn more and more about it and I will get better and better at imaging, allowing me to use larger telescopes and longer focal lengths with a fairly smooth learning curve. I find that new users most often underestimate the value of spending a long time with a single mount and learning its nuances. Other good choices if you are going to spend this much money are a used AP-900 (varies, but around $6k), a Tak EM-200 ($4000) or NJP ($5500).
  • That leaves between $4000 and $6000 for telescope and camera. Some good combinations for starting out, IMO:

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


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