Combining Filtered and Unfiltered Data?

[Smithynova]

Hi guys, 

I have been imaging the Rosette nebula for the last 4 nights (clear nights coming like London Busses!) using my Redcat 51 with ZWO ASI 183mc Pro, however, I got hold of a Optalong LeNhance filter yesterday which I used for the 4th night of imaging. I live under Bortle 4 skies here in Dorset so the data from the first 3 nights is ok. I've got nearly 5 hours of 300second subs unfiltered and about 2 hours of 600second subs using the filter.

My question is - can I combine data from all 4 nights - even though 3 of them were unfiltered and if so when is the best stage to do this - when stacking or in photoshop? Or would it be better to only use the data from the filtered session?

Thanks in advance

 

Tom

[geordie85]

Personally I'd stack them separately then use layers and masks in Photoshop to add the details and maybe a bit of colour from the filtered data.