Dark Calibration Stopped Working?

[Al Fleming]

What have I done? Tried calibrating my NB subs of NGC6960 but found that post calibration, there was the same amount of noise as before. Verified this by calibrating with and without Darks and got same noise distribution. Flats calibration worked OK. Don't know about the Bias calibration result. Until this point, PI calibration has worked perfectly. What error has the operator made this time? Thanks, Al

[Carlos Milovic]

Did you see any flags by ImageCalibration regarding the darks scalation? Maybe it showed a warning message saying that no correlation was found, and used a 0 valued scalation factor.

[Al Fleming]

Thank you for responding Carlos. Detail from the processing console: Dark scaling factors:

k0 = 0.254
* File already exists, writing to: C:/Users/Alistair/Astroimaging/NGC6960/NGC6960-005Ha_c_2.fit
Writing FITS image: 32-bit floating point, 1 channel(s), 3326x2504 pixels: 100%

===== ImageCalibration: 1 succeeded, 0 failed, 0 aborted, 0 skipped =====
2.917 s

Some more info: I had optimize ticked. If I don't tick it, I get a 'silverey' image. Regards, Al

[Al Fleming]

I've done more testing on this and remain confused. My darks and biases will still calibrate RGB or L subs, but they will not calibrate my narrowband subs. Why would this be, please? (I did not calibrate for Flats in either case to exclude possible errors in my master Flat generation.) Thanks, Al