Adam's preference of "7 or 11 flat frames"

Patrick Bisaillon

While listening to the FastTrack 2022 : Open One Image lecture, Adam mentions he likes to take either 7 or 11 flat frames. I'd be curious to understand why sometimes 7 is the what you are going for versus 11 in other occasions.

Thank you

BlockHead

The odd number is useful for a median if ever desired... other than that... really not much difference. 

They are lucky numbers right? Flats contain lots of signal and low noise for the stuff that interests us. If you are doing photometry.. you need to minimize the noise by taking more flats.

-the BlockHead

TimPilot

Hmmm, makes me think I am overdoing it by taking 30 flats!!

BlockHead

Flats have a bright signal. You are not doing photometry (measuring the light with precision). You just want to get rid of the major issues. Generally a smaller number will be fine. 

-the Blockhead