Using multiple flats and darks in Batch Preprocessing

[Astrodoc]

In BPP, the tool tips for using master calibration frames all say that the first master dark, bias or flat will be used.  However, I did some experiments that showed different master flats are used for lights acquired through different filters.  Also my results showed that the first master dark is not necessarily used.  Perhaps this could be clarified in the tool tips in BPP.  Here's what I did:

Method:
I painted annotations on  5m- and 10m master darks and on red and blue master flats.  This allowed me to see which calibration frames were applied to each light frame by BPP.
The annotated master calibration files were loaded into BPP, along with a master bias
5m and 10m Red, and 5m and 10m Blue light frames (four frames in total) were calibrated using BPP

Results:
See https://www.dropbox.com/s/4oi3ajzgppe8loe/Screenshot%202015-05-26%2020.53.52.png?dl=0

Filters and exposure duration are included in the file names.  The annotations on the screen show which dark and flat were applied.

- BPP used the 10m dark on all four light frames.  The 10m dark was not the first dark listed in the darks tab.
- BPP used the red flat for both red frames and the blue flat for both blue frames.

Although I don't bin for my own imaging, I imagine that if only one master dark can be used, you'd need to do separate runs of BPP for binned and unbinned files.

Clear skies,
Ron

[Warhen]

Dr. Ron, No one ever seems to want to touch questions on some of the BPP features which seem to be shrouded in mystery! ;>) As you and I agreed privately, multiple flat masters DO work, and while you can't use multiple dark masters, the longer dark should bias scale fine for lights differing in exposure time. Seems to be a small error with the floating tool tips as you point out.

I realize most don't use BPP for more than calibration if that, but it is a very handy script for many. I think adding the ability to choose an integration reference image as with ImIn would go a way towards making it that much more viable.

[RobF2]

Thanks for sharing this.  I guess we could dig into the code, but this is very helpful.

I was just scratching my head wondering whether to shoot 10min darks in addition to the 20mins I already had (after shooting max 20min Ha exposures in a recent session).  No need if its always scaling down.

[RickS]

I guess we could dig into the code

Use the source, Luke