[Startrek (Martin)]

So being on a high with confidence that I’ve finally nailed the issue , I thought I’d stack Ha , Oiii and Sii data with out Cal frames and then load into Startools via Compose and cross fingers no pattern
You guessed it , after an AutoDev stretch , background has checkered pattern again
So I just tested each data set individually in Startools and yep checkered pattern again but what was interesting the Ha and Oiii images had the checkered pattern running NSEW but Sii had it running at 45deg corner to corner
Buggered if I know what to do next

I captured 2 nights of Ha , 1 night of Oiii and 1 night of Sii

If I stack 1st night of Ha without calibration, image is perfect

If I stack 2 nights of Ha without calibration image has pattern NSEW

If I stack 1 night of Oiii without calibration image has pattern NSEW

If I stack 1 night of Sii without calibration images has pattern at 45 deg corner to corner

In DSS I’m using a reference frame to align the separate channels, however individually each channel still has the pattern ???

Doesn’t make any sense at all ??
Faulty sensor ??
Frost on sensor ??

Any further suggestions other than try another stacking software??

I do use ASTAP for reviewing subs only , does anyone have procedures and recommended settings for registering and stacking in ASTAP using Ha , Oiii and Sii or LRGB mono data sets
Startools has a brief guide using ASTAP but how do you align your stacks so they are exactly the same size and alignment. Startools Compose requires stacked data sets identical in size to be able to load and process

Martin