I’m new to SGP, and trying out my kit with it. Last night was a run to try auto focus. Having tried and failed miserably with Maxim in the past, so was pleasantly surprised to find sgp gave nice repeatable v curves.
So tonight, after a bank of clouds, I set up to see if my filters were parfocal. Tried for three hours, and could not get a single good v curve, on lumminence, let alone the other filters. Thinking of taking up knitting, at least I could do it in the warm