Quote:
Originally Posted by lazjen
Should be easy Rick - it'll take me a while to understand things enough... 
Ok, we're aiming to solve T given we know or choose other parts of the equation. The main, difficult variable is S. Also, for practical purposes (darks), we're going to limit T to various values (60 sec, 600 sec, etc).
The sky signal will vary based on the time of the night, phase of the moon, etc. Is it best for T to be such that you're under sky-limited exposure length, or is going over ok (but "wasting" time)? |
Chris, Ray has produced a very useful chart that shows optimal broadband sub times for differing Gain settings , for three different f ratios and two different levels of darkness (SQM), it is published in the ASI1600 thread here.
I would suggest eliminating variables such as moon effect, and time of night light effects ( like nearby sports fields, neighbors, etc).
Of course narrowband is not as suscepable to 'external influences' imho.