DeepSkyStacker is a freeware for astrophotographers that simplifies all the pre-processing steps of deep sky pictures.

• Registering
• Stacking
• Simple post-stacking processes to quickly view the final result.
• Saving the resulting picture to a TIFF file (16 or 32 bit)

After a shooting night you give all your pictures (light frames, darks frames, offset/bias frames, flat frames) to DeepSkyStacker and you go to bed. The next morning (or is it afternoon?) you can see the result and start post-processing.

Features:

• Automatic registration of a set of pictures
• Automatic detection of stars using all the picture area
• Preview of registered stars
• Sub pixel registration
• Automatic derotation
• Automatic creation and use of offsets, flats and darks frames
• Sub pixel alignment and stacking
• Supported bitmaps formats : 8, 16 and 32 bit colour and monochrome TIFF files, 8, 16, 32 and 64 bit colour and monochrome FITS files, JPEG, BMP, PNG
• Native use of RAW files from most DSLRs (CR2, NEF, CRW, ...) without using an intermediate file format (TIFF or other).
• Darks, Flats and Offsets computed from and applied directly to the RAW picture before any interpolation.
• Stacking methods: average, median, kappa-sigma clipping, auto adaptive weighted average, entropy weighted average, maximum...
• Preview of all pictures (including RAW)
• Simple post-processing with RGB levels, luminance curve and saturation adjustments.
• Save the resulting picture to 16 or 32 bit TIFF files with or without adjustments applied.
• Simple and intuitive user interface
• Optimal memory usage: the same amount of memory is required to register and stack 10 or 500 pictures.