canon plus lightbridge...

[bkm2304]

Hello photobuffs,

If I want to stick a Canon 400D on the end of my Meade Lightbridge and take photos - forgetting for a moment the teensy weensy issue of actually tracking stuff! - how do I do it? Do I take the lens off, where do I get an adaptor etc etc,

Thanks

Richard

[iceman]

For a dob without tracking, your best bet is afocal imaging.. so leave the lens on! Point it into the eyepiece and shoot away.

You can get camera adapters that hook onto the eyepiece and hold the camera in place. There might be some balance issues with the dob that you will need to overcome but it can be done.

This article is over 2 years old now, but still holds value: Astrophotography with a dob (http://www.iceinspace.com.au/index.php?id=63,201,0,0,1,0)

[bkm2304]

Thanks, Mike. So the camera will autofocus looking at say, a brightish star through, say, a 26mm eyepiece? Also, what would be a guestimate for seeing the faintest object after say a 7 -10 second exposure? I know this is very hypothetical but if I look and see visually a mag 12 object, will a shortish exposure as above, see any better?

[iceman]

I doubt the camera will autofocus - you'd need to manually set it to infinity or if it's a DSLR then manually focus it.

You won't be able to do a 7-10 second exposure - you won't have tracking remember :) You'll get star trails. You'll mostly be limited to shots of the moon and planets. You could try a 3 seconds exposure through a widefield eyepiece on something like a bright glob, and with a high ISO you might get something, but don't expect great results using this method on an untracked dob.

A shorter exposure means less light coming in, so the object will have to be brighter to register on the CCD.

For non-tracking dobs, stick to planets/moon - and get a webcam! :)

[CometGuy]

Richard,

If this is a 16" dob you will be lucky to get much more than 0.1-0.2 second exposure before trailing occurs (and this assumes there is no shaket from the camera shutter/mirror). With a 10 second exposure (assuming you use a tracking platform) you should see more than your eyes alone.

Autofocus is not possible with the telescope.

Terry

[jjjnettie]

If you have a video camera, use that instead of your 400d. You'll get better quality images from stacking avi's than from a single still.

Can you take avi's with the DSLR's?