Multiple WBPP stacked .xisf's

Habib Sekha:
Hi, see the second post there:

https://pixinsight.com/forum/index.php?threads/wbpp-ignores-exposure-tolerance.17768/



In your case you might want to set the tolerance to 200 seconds or higher.

Thank you Habib. Just curious, what method do you use to arrive at the recommended Exposure Tolerance? I'd like to understand how to determine that value for future stacking projects.  After experimenting, I'm guessing I raise the value until all the subs combine into a single post-calibration line?

to answer you main question: each of those stacks you have correspond to different exposure times, so, none of them are a composition of multiple exposures

if you're using Keyword grouping (which I recommend doing), and if you want to combine differing exposures into one stack, then you need to check Pre, and leave Post

this causes all the subs to be grouped according to the Keyword, in the preprocessing stage, then to all be stacked into one, in the post

like this:

here, in my case, my Keyword is Session, which is the name of all the individual folders containing my lights and flats per session per DSO (each folder containing flats and lights is named Session 1, Session 2, etc..)

I'm not sure if this is necessary, but it does simplify things, especially when using calibration frames taken per session

if you were to check Post and Pre, then they would be grouped by the Keyword both in Pre and Post, meaning, it'll make different stacks per exposure time instead of stacking everything

but even with this, you need to set the exposure tolerances to allow the differing exposure times, like Habib mentioned

if you planned on doing an HDR composite, then I think you're actually fine with stacks separated by exposure time - just put them into HDR composition (Process --> all processes --> HDR composition), and you'll get an HDR composite image

my 2 cents