Problem stacking

[SAW]

Hi,

Why has this data not stacked correctly ? It was shot with a modded dslr and a 12Nm Ha filter. A single sub looks fine, I've Blinked though them all and used subframe selector to find the best one as the reference image for stacking. I've tried with flats, flat darks and with no calibration frames at all, even in DSS is comes out the same ? 31x600s and 20 flats and 20 flat darks. Even when I extract the red channel it looks just as bad.

[pfile]

that looks like what happens when you stack unregistered frames... are you using BPP or WBPP or doing it manually?

rob

[SAW]

BPP

[pfile]

since it's a DSLR my best guess is that with Dark Optimization turned on, there are too many residual hot pixels left in the calibrated frames. StarAlignment (which gets called from the BPP script) is presented with a huge number of these hot pixels which it has interpreted as stars, and as a result registered all of the files with no offset at all. so the c_d_r files are identical to the c_d files. it then stacks the c_d_r files but since they aren't actually aligned on the real stars, you get what you ended up with.

you need to increase the noise scales and the hot pixel suppression in StarAlignment but i'm not sure you can do that from within BPP. you might have to run StarAlignment manually.

rob

[SAW]

I had dark optimization turned off, guess I'll have to try and stack it manually.