Best OTA for EAA in heavy light pollution
Posted: Tue Jun 01, 2021 4:45 am
Hi everyone! I'm new to EAA and am currently using a C6 evolution with focal reducer and asi385mc camera. I also live in a bortle 9 city. Sharpcap is an amazing program. I absolutely love it.
I have read all your articles on optimal exposure times and found the math very interesting.
Here is a question that I haven't found a satisfactory answer for: How does the f ratio of a scope affect EAA? How does it change optimal exposures? Does heavy light pollution favor fast scopes or slow ones?
In my case I am thinking about getting either a rasa 8 focal ratio 400mm f/2 or a 73mm refractor f/5.9. I suspect the rasa will be better but I would like to be sure. Also either one would be used on my evolution alt AZ mount and exposures should be limited to 20s max. Seeing and transparency are often good or above average at my location.
Thank you for your help!
I have read all your articles on optimal exposure times and found the math very interesting.
Here is a question that I haven't found a satisfactory answer for: How does the f ratio of a scope affect EAA? How does it change optimal exposures? Does heavy light pollution favor fast scopes or slow ones?
In my case I am thinking about getting either a rasa 8 focal ratio 400mm f/2 or a 73mm refractor f/5.9. I suspect the rasa will be better but I would like to be sure. Also either one would be used on my evolution alt AZ mount and exposures should be limited to 20s max. Seeing and transparency are often good or above average at my location.
Thank you for your help!