Imaging through a Dobsonian?

[davo]

Hellooo.

No imaging experience so be kind etc.. I have just seen an image somewhere on this website of the ISS, (sorry i don't know how to do the link thing), and it was taken with a dobsonian & webcam!! I'm really amazed!!!! and never knew you could image objects this good with a Dob. I a very keen visual observer and have been using binoculars and very recently a proud owner of a 12" Dob and I am just wondering what else can be imaged through a Dobsonian? I'd never thought of it!

Thanks

:scratch:

Dave

[themos]

Crescent moon mosaic (afocal, 12" Dob)

http://ukastronomers.com/themos/image/2826_large.jpeg

Mars (afocal, 12" Dob)

http://ukastronomers.com/themos/image/3366_large.png

Gassendi crater (afocal, 12" Dob)

http://ukastronomers.com/themos/image/3984_large.png

I used a Canon Powershot for these afocal shots.

[davo]

Thanks for the post. I was beginning to think I had posted in the wrong section and was maybe being frowned apon by purist imaging astronomers. I like your Moon images and surprised to see you got Mars!. I don’t have a DSLR but I am wondering if a reasonably priced webcam would be worth getting for my Dob? I have no idea what can be achieved imaging wise.

Cheers

Dave

[themos]

Believe me, I was surprised too!

The problem, as I recall, with webcam+dob is the very small size of the webcam sensor, a handful of millimeters. Also, a 12" Dob will probably have a focal length of 1500, so I end up with 10.5x9.1 arcminutes in the webcam sensor. That's quite a challenge.