Does anyone know where I can find pictures that correspond to the size of the lens on a telescope?

Answer 1

Jansen -

Not sure what you mean. If you look in magazines like Sky and Telescope, they generally list the types of scopes and magnification that were used with each photo. Also, most sky chart software packages allow you to create a circle that you can tailor to your individual eyepieces (or to the circles on a Telrad), so that you can superimpose them onto a chart to get a better idea of what to look for in each eyepiece - remember also to flip / invert the view, depending on what kind of scope you are using. I have found this to be a useful approach to star hopping - I create the evening's charts before I go out - if I don't have them already - and I am better prepared for what to look for at the eyepiece. If you need freeware that does this, I would recommend:

http://www.stargazing.net/astropc/

Answer 2

Hi.
If you're thinking what field of view would be best for imaging then there's a wonderful free download called CCD Calc, made by New Astronomy Press. The link is here.
http://www.newastro.com/newastro/book_new/camera_app.asp
If you tell it what camera and telescope you are using it will bring up a little box showing you what it will look like as a final result. Brilliant bit of kit IMHO.

Answer 3

There are several sites like this. Here's one by a very reliable observer, Roger Clark:
http://www.clarkvision.com/visastro/m51-apert/index.html