Hello All!
I am delighted to introduce you my new software called Perfect Exposure. As its name implies, it will help you to calculate the minimum exposure time depending on your camera parameters and your real sky conditions.
Perfect Exposure (very low cost) can be purchased here:
http://www.skymonsters.net/software.php
It is currently available only for Windows platform but if you are interested in a Mac or Linux port let me know.
Clear skies
Nicola