Min star size during autofocus in

i accidentally tried to run auto-focus with my camera cooler turned off. i found that SGP was detecting hot pixels as stars and was unable to complete an autofocus run. i thought the “min star size” setting (which i have set to 6 pixels) should have avoided this problem, but it seemed to have no effect.


pfile - I think there is a dark frame feature available that can remove that, in the settings.

yeah i know about that, i don’t normally need it. but i thought the AF algorithm was supposed to be tolerant of hot pixels??


Six pixels is pretty small. It’s easy to make a star from that… one pixel and a couple random pixels of randomly fading noise and you have a star. You should really be somewhere around 10-14 to avoid that.

ok i’ll increase that. many hot pixels were detected as stars but then again with millions of pixels in the image it stands to reason that it could happen.

You can also keep the cooler off and test this setting in real time. Turn HFR on for FF and change the min pixel size between frames.

will do, weather looks bad for more than a week so going to have to postpone any experimentation for a while.