[Slawomir (Suavi)]

Hi Lee,

SuperBias will generate a noise free Bias frame that will only contain patterns introduced by the camera. So by subtracting correctly made SuperBias you will remove some camera-introduced patterns from your Lights without introducing additional noise. Then, if you only used a defect map you should end up with cleaner images. Noise in your Lights though should remain the same. I think we should keep in mind that subtracting perfect noise free Bias and noise free Dark frames will not bring the noise down in your Lights, but will only remove camera introduced artefacts. Bringing down noise is done by correct stacking of a number of subs, and optionally by noise reduction techniques in processing of the image. That's the way I see it anyway, and will be glad to be corrected if I am wrong.

EDIT: just to clarify, MasterDark contains Bias so you would not be subtracting both from your lights. However, in theory, calibrated/scaled MasterDark and MasterBias are both needed to properly prepare Flats.