Prospective setup questions...

[jetskilz]

Feel free to chime in with any advice in any of what I'm about to post...

So, after using my trusty and heavy 'ol TAL, I have decided to start looking to buying a scope with the dual purpose of observing and photography. I live out in the countryside now, with incredibly dark skies, accessible in my back garden.

I've been considering getting the Celestron Advanced C8 NGT, although I'd really like the C10, but with skies like these, I shouldn't need THAT much of a light bucket. Also, I think the 10 would be too much strain on the mount when imaging. It would come on the CG-5 GOTO mount. I decided on the Newt, as I won't be travelling with the scope much, and don't really mind the lack of portability you'd get from a S.C.

Since TAL eyepieces don't fit other scopes, I was looking at a mid-range Antares collection. A 25, 9, 7 and a 2x barlow should be good I think..???

I'll be imaging with a DSLR, Canon 1100D, as I think CCD's are still a bit out of reach financially. Mostly deep sky, but an "event" in the local system surely won't go missed.

Guide-this is where it gets tricky for me. I know nothing about guidescopes, and from what I can tell, a piggyback setup is ideal, with a small apochromatic refractor, and a ccd guide camera. Question here is...would Starry night pro 6 plus act as an accurate gide if controlling the scope?

Also, if there's anything else anyone would like to help out with (ie. experience with imaging using the aforementioned scopes) or anything in general, would be much appreciated.

Thanks!!

[Capricorn]

Puzzled, the Celestron C8 I can see is an SCT, you are saying it is a Newtonian.

I decided on the Newt,

From FLO's OTA only page:

Celestron's C8 has been a best-selling SCT telescope for decades with a reputation for optical excellence, lightweight portability and great value.

[jetskilz]

The C8 NGT is the newtonian equivalent...

Celestron C8-NGT Computerised GoTo Telescope [31062] - 794.00 : 365Astronomy: Discovery for every day!

[RikM]

You don't need a small APO as a guide scope, but it would probably be better than the C8 as an imaging scope, especially as dark skies would give you the option of wider fields of view and fainter targets.

Large aperture is not required for DSO imaging, focal ratio is what really matters. You will want a fast scope less than f/8 certainly and the faster the better really. If you can stretch to it, a small APO for imaging with a finder guider and an 8" Dob for observing would probably be the ideal.

Guiding is not the same as GoTo. To get acurate long exposures you need to mount a second camera on a small secondary scope (a modified finderscope or ST80 is ideal for this), guiding software then looks at a selected star in the image from the guide camera and sends corrections to the mount to keep the guide star where it's supposed to be. Tracking motors are not normally machined accurately enough to keep stars small and round during exposures that run to several minutes at a time unless an autoguide system is used.

[jetskilz]

You don't need a small APO as a guide scope, but it would probably be better than the C8 as an imaging scope, especially as dark skies would give you the option of wider fields of view and fainter targets.

Large aperture is not required for DSO imaging, focal ratio is what really matters. You will want a fast scope less than f/8 certainly and the faster the better really. If you can stretch to it, a small APO for imaging with a finder guider and an 8" Dob for observing would probably be the ideal.

Guiding is not the same as GoTo. To get acurate long exposures you need to mount a second camera on a small secondary scope (a modified finderscope or ST80 is ideal for this), guiding software then looks at a selected star in the image from the guide camera and sends corrections to the mount to keep the guide star where it's supposed to be. Tracking motors are not normally machined accurately enough to keep stars small and round during exposures that run to several minutes at a time unless an autoguide system is used.

Don't think the wife (Vader of my astronomy) will let me go for an APO and a 8" dob. She's already slightly annoyed at the presence of the modest 4.5" TAL out back.

I've been looking at the Orion "Awesome autoguider" and the "Magnificent mini-guider" package. Any thoughts on those setups?

[Capricorn]

Two C8 options, weird.

Main concern is that the mount displayed does not look that solid.

If you put a Newtonian on then DSLR then a Guide system, the weight would be too much.

Also use the small apo as the imaging scope not as a guide, or just get an inexpensive small achro. The guide scope does not need to be apo.

Why a Newtonian as the imaging portion of the system.

You would need to maintain good collimation and there will always be the prospect of diffraction spikes from the secondary spider.

[ollypenrice]

If you want a painless (or relatively painless!) introduction to deep sky imaging stick to a short focal length, well below a metre, because the guiding accuracy required is far less onerous. Fast F ratio has been accurately covered above. An ST80 or finder guider makes a good guide scope with no need for an apo, also as stated above. The standalone guiders sound easier but probably aren't. Go for a QHY 5 and free PHD software. They give more control and more flexibility in the event of a glitch. (Glitches are not unkown in imaging...)

Scopes that are good for imaging and good for visual do exist but tend to be for experienced or very patient imagers. I heartily recommend not trying to combine the two into one scope. Trying to do so may prove more annoying than having an annoyed wife.

Olly

[jetskilz]

Two C8 options, weird.

Main concern is that the mount displayed does not look that solid.

If you put a Newtonian on then DSLR then a Guide system, the weight would be too much.

Also use the small apo as the imaging scope not as a guide, or just get an inexpensive small achro. The guide scope does not need to be apo.

Why a Newtonian as the imaging portion of the system.

You would need to maintain good collimation and there will always be the prospect of diffraction spikes from the secondary spider.

I haven't gotten an APO as of yet, I was just asking about guidescopes in general. I've seen quite a few setups, apparently, they have a lot more dosh than I do. I was looking at achros, but didn't think they'd be decent enough as guides. I've been wrong before.

I've seen DSLR imaging with the same scope and mount, and it looks very nice. I've never been a fan of the refractor...perhaps it's a personal preference, might also have to do with how much I'd spend on a refractor I'd really like. I was originally going to go for the new quattros from sky-watcher, but as they don't come with a mount, and if you're not buying a CF tube, you're easily looking at an EQ6 synscan mount which is more expensive than the whole celestron set-up. Even the CF tubes are VERY cumbersome, and I can't see an EQ5 or equiv. really driving those tubes around.

I'm basically looking at spending about 2k in total including the DSLR which is the limit of my budget.

[jetskilz]

If you want a painless (or relatively painless!) introduction to deep sky imaging stick to a short focal length, well below a metre, because the guiding accuracy required is far less onerous. Fast F ratio has been accurately covered above. An ST80 or finder guider makes a good guide scope with no need for an apo, also as stated above. The standalone guiders sound easier but probably aren't. Go for a QHY 5 and free PHD software. They give more control and more flexibility in the event of a glitch. (Glitches are not unkown in imaging...)

Scopes that are good for imaging and good for visual do exist but tend to be for experienced or very patient imagers. I heartily recommend not trying to combine the two into one scope. Trying to do so may prove more annoying than having an annoyed wife.

Olly

There's worse than an annoyed wife? Who knew?

Thanks for the tips, seriously. I basically am allowed to spend my wife's equivalent that she spends on her horse...so after year's end, I'll probably be upgrading my imaging kit, and keeping the newt for strict observing. I guess what I'm doing is really just "popping the cherry" on imaging, making mistakes with the newt I'll be keeping for observing, and gaining some knowledge before sinking a small fortune on imaging equipment.

Does that make any sense? Or is it complete and utter American babble?

[ollypenrice]

Think again about refractors, seriously. In a world in which very little works (astrophotography!) the refractor has a strong likelihood of being one bit of the setup that does work. There are great little refractors out there which can do the business without cajoling. As for guiding , junk is fine but fast junk is ideal.

Olly