WBPP Setup for Multiple Nights and Exposures

Matthew Humphrey

Hello!

I started typing this question to the forum and as I was doing so, I figured out the answer to my initial question.  However, I have a couple additional questions.

I am trying to process data from multiple nights on the same target, and it isn't working the way I expect. Each night was with different exposure times.

Here is the list of files I have:

First Night:

116 Lights @ 180 seconds

30 Bias

30 Darks at 180 seconds

60 Flats

Second Night:

192 Lights @120 seconds

30 Bias

30 Darks at 120 seconds

30 Flats

I have organized the Lights and Flats into separate folders for each night.  All of the Darks are in a single (separate) directory, and all of the Bias are in another.

I have specified a Keyword in WBPP.  The Lights and Flats are each separated out correctly.  The Darks are grouped by exposure time.

With this setup, WBPP produces two master Light files.  In the "Post-Calibration" tab, there are two master light files listed, one at each exposure time.

Sure enough, after I run WBPP, I end up with two master light files.  

What I figured out is that I needed to increase the "Exposure Tolerance" setting to something large enough to include both exposure times.  Initial question answered.  

The follow-ups are:

Is there any reason why you wouldn't want to increase the exposure tolerance setting so that a single master light is produced?

And, after running WBPP with the default exposure tolerance and ending up with two master lights, what is the best way to combine them to get a single image?

**What I ended up doing is just re-running WBPP with the adjusted Exposure Tolerance value.  Is there a better way?

BlockHead

Followup #1 ... No. (in my opinion). Integrating different exposures times is handled well with proper weighting. Perhaps there is an argument for HDR composites- but this is a *weak* argument in my opinion.

Re-running is the best way. If you changed nothing else- everything would have been cached up to image integration... so it would not have taken too much time. 

If you did have two masters- you can duplicate each file (two of each, four files) and use image integration (without rejection) to combine them. This will take care of the necessary weighting.

-the Blockhead