M42 - Processing Light Subs of Different Length

[jwaters125]

I just got done imaging the M42 area.  I took 'Lights' and 'Darks' at 120, 80 and 40 seconds.  I used a Ha modified Canon 6D and the Canon 200mm f/2.8L II lens.  I suspect I need to process each batch of Lights separately but how to I combine them within PI?

[RickS]

Integrate as separate stacks and combine with HDRComposition.