Hi - I get good v curves with my Lum filter but not so much with narrowband. I’m shooting with a small refractor around f4.8. I use 2x2 binning and 5 sec exposures with Lum and 25 with ha 5nm. I can’t get a good curve with the ha filter and many times the focuser winds up searching too large of a range and I have to cancel out of the routine.
I was thinking of trying to focus with Lum and using the offsets to get to focus with my narrowband filters. Is this what most people do? I would rather autofocus with the filter I’m imaging with but just doesn’t seem to work. Maybe I need to expose longer? Seems like PE in the mount would start to come into play with longer exposures (I pause auto guiding since I’m OAG). Appreciate any help.