Pixinsight master dark issue

[Spookyer (Brett)]

When I use the batch preprocessing script I am getting a message in purple in the processing window that says "Warning no correlation between master dark and target frames". It seems to be processing the flat frames at the time.

I don't understand this, I use a master dark for the sub length that was created from a previous image I processed. You get your registered images etc and in the master diectory is puts the masters. I just copied this to a general master directory and I then use this master dark for every 10min sub project.

Is there some other way I was supposed to create a master dark?

[RickS (Rick)]

It's a warning message that means that applying the master dark results in a noisier result than not applying it, so PI didn't. If you're calibrating short flats with a much longer master dark then it's not surprising that you might see this. I get these messages occasionally as do a lot of other people (it's a question that has been asked a few times on the PI forum.) The only time I would worry about it is if I saw it consistently when calibrating my light frames.

Cheers,
Rick.

[Spookyer (Brett)]

Thanks Rick

[Geoff45 (Geoff)]

Originally Posted by RickS

The only time I would worry about it is if I saw it consistently when calibrating my light frames.

Cheers,
Rick.

+1

Recently I calibrated 30 flats (exposure<5sec) with a 600s master dark and master bias. I got this message on 5 of them--random as far as I could see. I eliminated these from the batch and calibrated the other 25 with no problem. Usually though I just use a master bias when calibrating flats. The dark current is negligible.
Geoff