Selecting a New Setup

I am relatively new to astronomy, but am an old hand at imaging (I'm a professional photographer). I need help selecting a telescope system. I will be using it both visually and for astrophotography, the latter with a large DSLR. The OTA and the mount must be TOP quality and high performing. The setup should be relatively easy to use with GOTO mount. I'm looking at Celestron C9.25 Edge, Takahashi Epsilon and 210M, Astro-Tech RC 10", Vixen VMC260 and VC200L. What setup do you recommend and why?

Thank you in advance for the advice!!

First things first David.
You must first decide based on the image scale provided by the camera and scope combination. It should be something that your sky conditions will support well. It also should be something that will capture the types of objects that you favor.

Then, the scope needs to provide a corrected image circle size that is compatible with your camera CCD chip size, so that it is not vignetted. This may require a field flattener, depending on the scope.

Reflectors are usually more difficult to use, due to mirrors moving, weight and flexure issues. This must also be considered, as it is no fun to deal with them. Generally refractors are easier to deal with on this.

The mount must be chosen according to the weight and moment arm that the imaging rig load places upon it. Over mounting is always preferred to a mount that is barely adequate.

Cost factors must be figured in to the equation and then distributed accordingly, with the mount being one of the biggest considerations.

Sorry to not give a simple and straight answer, but unfortunately it is not a simple and straight forward question.

You already have two good answers.

And here is the point you don't want to hear---your professional photographer stuff is of good, but limited use. You are ahead of the rest of us in Photoshop, I am sure. And that is particularly true of the post-post processing parts (cleaning up, noise, and such). You have some to learn about stretching the data at the beginning. But, you will pick that up.

It is in acquisition that you will have the most to learn. Get the best mount you can find, as has been mentioned. And start with the widest Field of View (shortest focal length) to learn the tricks of alignment, guiding, etc. I would strongly suggest that you make no decisions at this point regarding a tube. Instead, buy the best mount you can afford (see the previous post) and stick your existing DSLR on it, with whatever camera lens you choose to use. The shorter the easier to learn, although 300-400 mm is well within reason with a quality mount.



Try that for six months while you are deciding what kind of things you want to take pictures of out in space. Get all your mount issues, software, guiding, and all that working automatically. Then it is time for longer focal length exposures.

Alex

David;

- Amateur astronomers are warm and encouraging as a group. It's a wonderful hobby and there are not many of us. It's a hobby that takes a great deal of patience and in the end, the thrills are subtle, seeing a detail or a faint galaxy or imaging something that is a challenge for an amateur but can be seen much better with Google. We want to share the joy and bring new members into the hobby.

But at the same time, we want to be honest and avoid deception. That is why you are seeing some discouraging posts, long exposure astrophotography is exceedingly difficult. It is tedious and there is a lot to understand and a lot of chances to ruin a photo. Doing it at a high level, requires some expensive equipment, expensive being tens of thousands of dollars.

This image by Roland Christen is quite amazing but look at the exposure times...

http://geogdata.csun.edu/~voltaire/roland/m82.html

Some thoughts:

- Astrophotography and visual observing are really two different hobbies and the equipment that is suited for one generally is well suited for the other. Visually, the telescope is most important. What you see depends on the aperture (diameter of the objective), bigger will show more detail. Telescopes are a focal so focal length is not so important.

- As the others have pointed out, astrophotography is a different ball game. I suggest looking at Jerry Lodriguss's website, he has some great tutorials:

http://www.astropix.com/HTML/I_ASTROP/TOC_AP.HTM

- The most important piece of the puzzle is the mount, not the telescope, not the camera. Long exposure astrophotography requires incredibly precise tracking. If you are shooting at 1/30th of a second, you need a solid tripod to avoid blurring the image. Now imagine you are shooting a 5 minute exposure of a moving target. Your mount needs to track the rotation of the earth accurately enough so that over that 5 minutes, it does not deviate a single pixel, otherwise the image is blurred. Even with a short focal length refractor, short in being 600mm, ideal to begin with, a single pixel will probably represent only a few arc-seconds. Just aligning the mount properly might take an hour...

- DSLRs are nice cameras and they are capable of taking some nice astrophotos but to really take high quality astrophotos one needs a dedicated monochrome astro camera and if you want color, separate exposures are taken with filters.

- I don't know how much experience you have with astronomy, it is a wonderful hobby and spending a night under dark skies with a telescope, it can be a life changing experience. But start with reasonable sized steps, get to know the sky, get to know your subject, start with a good quality visual telescope and spend some time learning your way around. Attend a star party, spend some time with the imagers and see what they are doing and how they are doing it.

Jon Isaacs

David,
I will echo a lot of what has been said already. Some of the scopes you mentioned have fairly long focal lengths and weight to them. For the best possible photos this will mean the best mount you can afford plus some. For visual use, the target object can move around wuite a bit without you even noticeing but the camera records all, so the sky conditions and mount/guiding become the limiting factors.

There is no one scope suitable for all objects. Star clusters want the largest diameter scope (for seeing the faintest stars) you can track with, while a large nebula will need a much wider field to contain the object. In sky photography wide field amounts to 400 to 500mm focal length, for objects like the veil complex 200mm or so is needed. Detailed globular cluster photos 2 to 5 thousand mm focal length is needed, along with good seeing and the most stringent requirement for the mount.

DSLRs become limited in how faint an object you can image due the the amount of noise. Local light polution has to be taken into account but can camera noise usually becomes the limiting factor.

By the way did I mention it is an awful lot of fun? The learning curve can be steep and frustrating at times but that is true with any endevor.

Dale

You've gotten some good advice, which I won't repeat. One thing you should not do is try and learn too many things at the same time. You will become extremely frustrated if you do. You need to learn the basics about the night sky and telescope operation before attempting astrophotography. It won't take a ton of time, but it won't happen overnight either.

It would be difficult IMO to start with an AP900, even though it is superior choice. It wold be a little like a a newcomer to sailing starting with a 40' racing sailboat. AP has a stellar reputation producing the highest quality of devices...except for documents. They assume you are already knowledgeable in the basics of amateur astronomy - a pretty safe bet normally.

An SCT like a Celestron or Meade is a great way to learn about what you are about to enter into IMO. If you really catch the Astronomy bug, you'd probably keep the scope anyway to kick around at parties and with neighbors. I know I do.

Your DSLR will work fine with one, even though there are problems that are not fixable, with an SCT/DSLR combo. It will still product nice initial results and provide you a nice platform to learn on. These scopes are made with the newcomer in mind IMO.

No matter what direction you go, don;t take on too many things to learn in one night. Too many degree's of freedom will almost certainly product a terrible experience unnecessarily IMO.

Good lucky

Russ