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Originally Posted by doppler
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Thank you Rick,
I actually read that exact same site this morning. That coupled with the experience I've had with my last OTA has made me draw up a bit of a table for my settings. In my current skies, I'm never going to get the best out of my new scope. Having said that, I think I've worked out a balance. I'm going to run several diffenent exposure times tonight and record the out comes. From that site, ISO 800 seems to be the best SNR for my camera which is what I ran last night. The problem is, even at 22sec, the sky washes everything out. Tonight's recordings will be as ISO 800 and iwouldnt just run small sets at different exposure lengths to record the point at which sky glow is acceptable. Given that the moon is at nearly 90%, this will become my worst case scenario. In 1 1/2 weeks when we get back to 50% moon, I'll run the same test and record my findings. Finally in 2 1/2, I'll run the same test with a new moon. My old setup was slow enough that it would sit within the tolerances of my mount in these skies. The 22sec came from that was all I could rely on the smoothness of my mount for. 22sec at ISO 3200 created small sky glow but tolerable with a full moon so I never had the options I do now.
Along the way, I plan to carry out the same test in diffenent skies to create a long term table as reference. Needless to say, going f/5 has created some challenges for me but I'm loving the data analysis and the opportunity to create a good reference table for my subs. An opportunity I've never had.