which stacking method?

[Joshua Bunn (Joshua)]

Hi,

Im curious to know which stacking method everyone uses to combine their lights, darks and flats? So it could be sum, mean, median, sigma reject, or min/max (if thats one).
When Sigma reject is used, is it used with a mean or median, if that even makes sense? I read somewhere on this forum that sigma reject performed the stacking in one pass whereas it took 2 iterations for one of the other methods - dont know where though.

Thanks
Josh

[alpal]

Let's say you have a galaxy and a noisy background.

I do 2 stacks:
(1) for the background with everything set to median
(2) the other with everything set to Kappa sigma clipping.

You can then combine the 2 images in layers with Photoshop.
You'll get a smoother background & sharper details in the brighter galaxy.