Question about image streaks

[astropixel]

Windsorised with a large stack - 266 images. I follow the tips and select accordingly, so it could be Linear.

[astropixel]

However, calibration has just finished. I notice dark scaling factors, in the majority, of 0.12 - 0.25, with a significant portion of 0.5 and several of 0.9 - 1.1. Reading your other post, should I remove any images affected by high dark scaling factors - 4 to 5 at the most.

[pfile]

that's interesting, i've never seen darks scaled down so much. usually i see ~0.85-1.1 as scaling factors. these low scaling factors are probably contributing to all the hot pixels left around. what happens if you turn off dark optimization?

as for the stacking method... what sigma factor are you using?

[astropixel]

Windsorised Clipping - default settings for the large set.

Here's the same 10 images selected at random - the top with dark optimisation, and the bottom without.

Streaking is not evident and I don't see any 'red' hot pixels. I notice that MRS defaults to k-sigma on images of 15 seconds or less taken at f/3.2 with no filter. MRS succeeded on all frames of 20 seconds or more - restoring my faith in the master bias and dark.

Now to the flats -

[astropixel]

Thanks for your help everyone. On to the next saga