Lookings for a little help here. I have the following setup:
Televue NP-101IS (540mm FL)
Celestron OAG w/ QHY 5L-IIM
SBIG STF-8300M w/ FW8-8300
I have been having mixed results with this setup in terms of guiding. I am always around 1.5-2” avg RA and Dec guiding. I normally let PHD choose the guide star. When I do this, often it loses the star. More recently I tried to choose my own with a little better brightness. Many of the brighter stars are peaked out. I have tried to choose a longer exposure which allows the faint stars to be more developed and I was hoping to average the seeing. This actually seems to not work as well as say 1-2sec. My gain has been around 10. Here is what I was thinking. Perhaps with the OAG, the very faint stars have a width far less than seeing (due to my long 540mm FL). PHD likes them due to the shape and picks them. I am thinking I need to pick a larger guide star by setting my QHY gain low to allow a deeper well. I will get only a few stars but they will be larger but not peaked and be less affected by seeing. I can attach logs if needed. Thoughts?