astrophotography questions

i got myself a new telescope, a celestron c8, its an older version but should do a good enough job to spark my interest. so i have my telescope, my camera, and my lenses, what else might i need to set this up for astrophotography, i dont care if i set the unit up piggy back, or through the scope, however how effeciant can it actually be through the scope? would it just be a 2000mm lens at that point

What kind of mount is it on? Is it motorised?

Yes the focal length is about 2032mm if you use it like a big lense. It's just a little awkward to walk around with it .

Get a T-Ring for the camera and a T-Adapter for the scope if you want to do prime focus.

e-k

its has the stock motorized base, i dont have any thing extra with it right now. i guss i shoudl take a picture of it so i can show what i ahve and what i dont.

I believe Celestron provided only GEM (German Equatorial Mount) and Fork Arm Altazimuth mounts. If the latter, then you would need a wedge unless you are just planning on taking quick snaps of the moon or doing star trails.

Other than that, with the T-Ring and T-Adapter you should have a good start. I would recommend getting a good book like Convington's on astrophotography or attending some local star parties.

e-k

i took some pictures of the moon today piggy back i guess. i put my camera about 50mm up to my eye piece, and then took some pictures, if they turned out i will post them later, i am unsure though if they will turn out.. although i will tell you that the moon is damn bright wiht that telescope, i as well saw Jupiter, i couldnt point out any of the land marks of the planet such as the red spots, or the color lines, however i could see a hand full of the moons, 4 i think. i only set it up in my yard, there was plenty of ambient light, so it was difficult to find stuff

Piggy back is generally just mounting your camera on top of the telescope and making use of the telescopes mount. If you were putting your camera with lens up to the telescope with eyepiece then that is afocal.

Hope some turned out for you

e-k

As e-k mentioned you will the a t-adapter for your scope and a t-adapter for your camera. Then you just mount your camera in the diagonal just as if it were an eyepiece. The C-8's drive should have no problems with the extra weight of the camera like smaller scopes like the Meade ETX or Celestron Nexstar series. Shoot with your camera in Manual mode. It take lots of experimentation to get the exposure right. Start with the moon, them move to some of the brighter planets like Saturn or Jupiter, and finally deep space objects (the Orion nebula is a good place to start). For the moon start with 1/125 sec and then step up until you get to 1/500 or even 1/1000. Good luck! Show us your results.

Here is a shot through a Meade LX90 which is very similar to your C8. This is actually 2 shots merged in Photoshop.

You should ask the member "nighthound"...his astronomical stuff is astounding, and he looks pretty willing to help out.

If you have a fork mount, which you most likely do, you will need a wedge for it, wedges are fairly expensive if you want a quality one. And with astrophotography at 2000mm focal length you defiantly don't want to skimp out on the mount. Astrophotography is more about your mount than anything, especially as focal length increases, above 1500mm is where it really gets tough as even a minor vibration such as the mirror slap on a camera can render your image soft or even a blurry mess.

If you have a equatorial mount don't worry about a wedge its not needed.

If you plan to to deep sky prime focus astrophotography (thats where you remove the eye piece and put a camera in its place) you will need a t-ring and adapter (usually pretty cheep), a guide scope or off axis guider (so you can keep your mount perfectly on track as even with motorized mount there is periodic error which you will need to compensate for other wise you end up with a blurry mess), and a focusing solution such as a knife edge focuser (you wont be able to focus through the view finder because it will be too dark, and attempting to do it by trial and error using the view screen after you snap a picture is very time consuming and very rarely accurate.

A focal reducer is also very useful as it will increase the field of view, lower the focal length and f/ratio usualy by about 40%.

So basicly:
Wedge $300-$400
Tring/adaptor $50
Guide scope $300-500 (or a off axis guide for about $200 but no where near as useful)
Knife edge/ronchi focuser $200-300
Focal Reducer $80-140

Prime focus astrophotography is one of those things where the money you put in is directly proportional to the image quality.


If you just want to take images of the planets (well Mercury, Venus, Mars, Jupiter, Saturn) with very little extra investment than you already have, you would only need the t-ring/adaptor and focusing solution. Your exposure time will be very short so you wont need to accurately compensate for the rotation of earth.

Also Piggyback astrophotography isn't too much extra investment, just need a wedge and a mounting bracket for your camera to sit on top. To focus just set the lens at infinity. This is probably the best way to start out actually, especially since you have a good selection of lens to do piggyback astrophotography, 16-35 for some nice wide field of the milkyway or the 100-400 for large nebula's, open clusters, and large galaxies. It is much much easier to learn the ins and outs of astrophotography at lower focal lengths than to dive right in to the very deep end at 2000mm.


Also be sure to check out the forums on http://www.cloudynight​s.com for more info on astronomy and astrophotography. Tons of info there, and the community is very knowledgeable and will be able to assist you with your setup, finding targets, imaging, and most importantly post-processing.

I read this thread but I didn't really see a definitive answer regarding what hardware is needed to hook-up an EOS camera to a C-8 Celestron. My brother has a C-8 he's going to let me try out so I know nothing about the two different styles of connecting the camera (EOS 30D)...Piggy-back or whatever. Does anybody know of a link that might be C-8 and EOS specific (or close to it?)

I've looked a bunch....but haven't quite found anything yet. Thanks for any input.....

http://www.astropix.co​m/

This site is full of useful astrophotography tips including different methods for mounting your camera and post processing. I bought the CD book and learned a ton. Not specifically what you're looking for but a good resource.

Do a search on astrophotography at http://www.astronomy.c​om

You will find some good links there.

I "THINK" you'd just need the Celestron SLR T-adapter & an EOS T-Mount Ring.

Celestron SLR T-Adapter Schmidt-Cassegrain Telescopes Part# 93633-A (~$35)
Kowa T-Mount (T-Adapter Ring) EOS part# TSPK-CE (~$23) (Celestron's is about $14).

I read on one of the forums that the Kowa T-Mount is the compatible with all the Celestron stuff (please verify this). I have just the Kowa T-Mount and it is definitely a high quality part. I use mine with a Kowa spotting scope & Kowa T-adapter. The T-Mount Ring is basically an EF mount that snaps into your camera body and then allows it to screw-mount onto the Celestron SLR adapter. I'm thinking that for about $60, you should be able to directly attach your Canon to the Celestron SCT scope and take pictures that way.

http://www.celestron.c​om/c2/category.php?Cat​ID=33

Do a search on astrophotography at http://www.astronomy.c​om

You will find some good links there.

You used a "good" title, so be sure to look at the "Similar Threads" links at the bottom-left of this page, too.

John_TX wrote in post #5756284
I "THINK" you'd just need the Celestron SLR T-adapter & an EOS T-Mount Ring.

Celestron SLR T-Adapter Schmidt-Cassegrain Telescopes Part# 93633-A (~$35)
Kowa T-Mount (T-Adapter Ring) EOS part# TSPK-CE (~$23) (Celestron's is about $14).

Thanks John, You hit the nail on the head. THis time Adorama blew B&H out of the water:

Adorama T-Mount for Canon EOS

Celestron T-adapter for all Schmidt-Cassegrains, Threads onto Rear Cell.