[tilbrook@rbe.ne (Justin Tilbrook)]

Originally Posted by IanP

Nice one, Justin.
How do you find all this stuff?
Another question is, and I have to investigate it with my 60Da, what is the max exposure vs ISO for DSLRs without dramatic overexposure of stars? (in your case 9mins)

Thanks Ian!

I use guide 8 software, and pan around to find objects that I may have not imaged before. It has an overlay with deep sky images for some of them. From there I go on the inter web to see if there any images taken by amateurs using similar setups to mine.
Sometimes it's just suck it and see.
Guide 8 also has quite extensive catalogues, some of which have descriptions of angular size brightness and visual descriptions.

For the second question, I don't know. The person that might is Richard ( rmuhlac ). He seems to have done a bit of research in best iso ratings.

Cheers,

Justin.