Kevin_A
Hi Kevin,
How do you test this when seeing conditions are always changing by the minute? I took out my new AM5 to a dark sky site last week and got decent guiding averaging around .4-.6 arcs seconds of error, and that was in fairly poor sky conditions with low transparency and mediocre seeing. I use an ASI220mm mini guide camera with a 240mm focal length guide scope, The asi220mm has a 4 micron pixel size compared to the ASI173, which I used to use which had a 5.86 pixel size.
But in the year I've been doing astrophotography I have never seen guide numbers stay exactly the same throughout the night.
Jerry