[Solved] Flats

Hi all,

I can kick myself for not being consistent in AP and after near a year I decided to get back into it.

I have taken M101 over the last few nights using my rig (ODK 14 inch which has corrector, and in-between I have a filter draw to mount my square LP filter followed by G4 16000 CCD and with all the filters.

I have dumped everything into the latest software of APP and left every at default and began the process, something which has worked well for me in the past. 

For some reason I am seeing terrible indented flats being applied at the final stages on process. 

After speaking with the staff who made the camera ADU should be around 30K with exposure 4 - 5 seconds 

My dark frames at 10 mins each  

Lights at 5 m each 

Bias 0s 

Flats 5s

I have tried without the dark and bias frames and getting the same result. My darks and bias frames are from February this year btw. 

When I am creating a master light frame and stretched I cannot these large bunnies!!  So I'm a little confused...

I have only taken my flats with SGP Pro, the rest was with voyager software. 

I'd love for someone to shed some light! 

Since this post I cleaned all the filters and I must say i didn't see much dirt at all!! 

Thanks in advance. 

P.S I have just stacked the lights only and darked the image via levels in PS.. Dam there is alot of bunnies