Starting point for DSLR astrophotography...

[stardad]

I was going to try connecting my DSLR Sony A350 to my Celestron 130 and CG3 mount to do some photo's with the children.

I guessed it would be on the limit of the EQ's weight. Now its got me wondering from another post about the A350 is it too good and big for what I want to do as a starter.

What sort of DSLR should you start with for Astrophotography? Its been suggested using a CCD and PC but that's not an option in my opinion.

[jgs001]

I don't see why you can't use the Sony... I've no experience of doing so though. What lenses do you have for the camera ? An option would be to remove the scope, mount the camera directly to the EQ mount and use the lenses... This will alter the weight mounted considerably.

I've heard, that the 130 scopes have issues with focusing with SLR's (not enough in focus), it may be you can remove the top of the focuser and find a t thread directly beneath, but can't confirm I'm afraid.

[Robd]

In answer to your question re What DSLR to sart with, the simple answer is 'The one in your camera bag' in this case your A350. The only difference in mechanical terms is that a non Sony will require a different 'T' adapter.

If as John says there is not enough 'in travel' on the focuser then you are stumped before you start. It may be possible to get a low profile focuser, not exactly cheap, or if you are lucky you may have a second set of mirror cell mounting holes that will allow the cell to be moved closer to the secondary mirror. I have 20yr old 10" Meade newt that allows this, but I do not know whether modern tubes do.

As John says you can just mount the camera on the mount using a Ball head. You can do some good wide angle for starters, then if you have a telephoto lens try it.

The beauty of the piggy back method is that that, other than a ball joint, you do not require any other fittings. (You can of course just fix the camera direct to the mount and use as if you were pointing the scope.)

Rob

[stardad]

Thanks.

So I'm limited by the focus where the EP's go.

I could screw the camera onto the top of the scope and take shots from there. Not what I had thought originally. Oh well back to the drawing board.

[Whippy]

I could screw the camera onto the top of the scope and take shots from there. Not what I had thought originally. Oh well back to the drawing board.

That's called piggybacking and it's entirely do-able but you may find the extra weight may cause issues. Why don't you give it a go and see how it pans out?

Tony..

[stardad]

What length lens do people use when piggy backing? I've got a 55-200mm telephoto and the standard 18-55 Sony lens.

I was thinking originally of using the daughters Hitachi compact but that fire's a flash when dark so is no good. I could go for a second Nikon D50 through the EP route for the kids but if I have to piggy back then its wasted cash. Going Pc route I'd have to buy a new PC plus CCD to do.

[old_eyes]

Piggy backing your DSLR will work pretty well. That was the first thing I did on my Nexstar 6SE, and guess what - pictures!

Not great pictures, but exciting, amazing, wow did I really do that, pictures.

With a 200mm you can get good images of things like the Pleiades, and other clusters.The Andromeda Galaxy (M31) is a maybe. I never got reasonable images of M31 until I used long exposures controlled by a laptop.

At the short focus end, you can get good pictures of entire constellations and chucks of the Milky Way. Have a look at some of the images of Orion on this forum. Last one I saw used I think 33mm focal length on a zoom.

Key question is how long an exposure you can make with your camera. Many give you up to 30 sec, and then you need plug in self timers or laptop control to go longer.

Even at 30 secs you can take a lot of images and stack them to improve signal to noise ratio in specialised software like Deep Sky Stacker (freeware from the web).

If we ever get a clear night again - get out and try it. Fiddle about. It's fun to get that first precious blurry and streaky image.

old_eyes

[Debostar]

I plan to get me the t adapter and t ring to use with my sony A100.....I am total new to this stuff, but we'll see how it goes...

[x6gas]

I really recommend that you see if you can unscrew the eyepiece holder from the focusser (you can on my Celestron C6). If there is a standard t-adapter thread then you can screw a t-ring on to there and that will give you enough back focus for prime focus photography using your Sony DSLR.

I've been pleased with the results I've had so far with a 30 sec exposure (limited experience so far thanks to the clouds!)

[x6gas]

I was going to try connecting my DSLR Sony A350 to my Celestron 130 and CG3 mount to do some photo's with the children.

I think you'll need a Minolta t-ring for your camera by the way. Available from all good camera (and telescope) shops and some bad ones (boom, boom!)

I'll get my coat...

[stardad]

I really recommend that you see if you can unscrew the eyepiece holder from the focusser (you can on my Celestron C6). If there is a standard t-adapter thread then you can screw a t-ring on to there and that will give you enough back focus for prime focus photography using your Sony DSLR.

I've been pleased with the results I've had so far with a 30 sec exposure (limited experience so far thanks to the clouds!)

I've just looked on mine. Take the EP out using the 2 silver thumb screws and the black ring attached to the focuser with these two silver thumb screws undoes (anticlockwise.) And its threaded! :D:D All I got to do now is work out what size the thread is for a T ring.

Cheers x6gas

[x6gas]

I've just looked on mine. Take the EP out using the 2 silver thumb screws and the black ring attached to the focuser with these two silver thumb screws undoes (anticlockwise.) And its threaded! :D:D All I got to do now is work out what size the thread is for a T ring.

Cheers x6gas

Great! The thread is standard on the 'scope side; you just need the correct t-ring for your camera as mentioned above.

Well done!

[stardad]

Thank you very much. If we get some clear sky and a Sony/Minolta T ring I'I give it a try and post some pictures. (Now where was that posting tip thread.)

[Debostar]

me too...when i get the t- thingys....