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.