Blink and you might.......

[Peter]

be as surprised as I was when doing a blink of my flats. The difference with some of the flats being a little brighter than others surprised me as they were all meant to be at the same exposure. But even better when I applied a histogram transformation icon on the blink icon they all appeared exactly the same. Brilliant, so I need to ask if this should be a common practice for all the bias, flat and dark files to be histogram transformed with the link module before calibration. I ask as I don't know if BPP does this automatically? Really pleased though to have found this out as a work of experimentation, shows I am becoming braver in my Pixinsight workflow. Now all I need to do now is produce a decent image.......one step at a time 

[pfile]

the flats are normalized by ImageIntegration before they are actually summed together, so it kind of amounts to what you discovered here. you just don't see it as it happens 'behind the scenes'

rob

[Peter]

Thanks for the clarification pfile, should have realised the gurus would have figured this out as standard. But loving the learning curve....