How do you autofocus? I am getting OK results on lum but struggling to get it perfect, narrowband filters won't focus at all : (

[pipnina]

I am using the Ekos focuser module, which I have heard some people have issues with. I try to get the focus as close as possible manually and then run the routine, set to whole field HFR, but it can often detect noise instead of stars, or detect multiple stars instead of just the one that is actually there. Then I end up with donuts.

I've tried switching from gradient to SEP, I've tried adjusting the sigma, kernel size and had it run 3 samples per hfr measurement.

Do you guys have a preference for conditions to focus under? Like a single bright star, using short exposures? Or a fainter star field (i.e. in the plane of the MW) with longer exposures? Single star where you select one, or multi star or whole frame?

Maybe even another program to focus with (Ideally linux compatible), since I have heard people have issues with Ekos' focusing.

How do you also determine the backlash? I have a zwo EAF and a crayford focuser which has some good tension on it so in theory I shouldn't have much if any backlash? I am also not sure how to get a very good quality set of filter offsets, since I think from what other people have said, focusing on Luminance is the best start, then set offsets for all other filters relative to it?

 

Thanks