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test processing with lights, flats and bias frames

red dwalf

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i`ve finally got round to doing some processing test to find out what difference adding flats and bias frames to my lights would achieve,

these where done using my Atik 314 L+ and processed exactly the same way in photoshop to get a proper comparison.

stacked in DSS, first lights only, then lights and flats then lights flats and bias frames.

saved as fit files instead of tiff but do not apply the changes to the saved images, it`s a little button at the bottom of the save screen in dss, if you do the image histogram goes right over to the right side and looks over exposed.

opened fit files in photoshop, i`ve found that there's no point in stretching the files in fits liberator before hand as the outcome seems to be exactly the same.

first i did auto levels on each image.

adjusted the levels down to the dark side,

simple standard curve on each image,

adjust levels again,

applied a low level gradient,

local contrast enhancement in actions,

reduced the noise in filters,

smart sharpen in filters.


here is the results and the histogram of each image, i think i prefer the one with lights and flats only but the one with lights, flats and bias has a wider histogram.


lights only






lights and flats images






light, flats and bias images





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