This program combines Flat Frames into a master flat. If run without parameters, a GUI window opens. If run given a list of file names as args, then those are immediately processed without the UI interaction. Video introduction and tutorial: https://www.youtube.com/watch?v=Rj6V3quA_2Q Files with same dimensions can be manually selected for combination, or you can point the program to a large set of files and have it automatically group them by dimensions, filter, and temperature and produce a master flat for each of the grouped sets. Preferences control how they are combined and where the result goes. You should always run the GUI version first, even if you intend to use the command line version, and use the Preferences window to establish some of the behaviours that will happen when the command line is used. Command line form: MasterFlatMaker --option --option ... <list of FITs files> Options -g or --gui Force gui interface even though command line used Precalibration options: if none given, uses what is set in GUI preferences -np or --noprecal No precalibration of input files -p or --pedestal <n> Precalibrate by subtracting pedestal value <n> -b or --bias <p> Use the given calibration bias file -a or --auto <dir> Precalibrate by with best bias file in given directory -ar or --autorecursive Recursively include sub-directories in auto bias file search -ab or --autobias Limit auto-selected files to Bias files only -ax or --autoresults Display specifications of each selected calibration file Combination algorithm: if none, uses GUI preferences -m or --mean Combine files with simple mean -n or --median Combine files with simple median -mm or --minmax <n> Min-max clipping of <n> values, then mean -s or --sigma <n> Sigma clipping values greater than z-score <n> then mean -v or --moveinputs <dir> After successful processing, move input files to directory -t or --ignoretype Ignore the internal FITS file type (flat, bias, etc) -o or --output <path> Output file to this location (default: with input files, used only if no "group" options are chosen) -gs or --groupsize Group files by size (dimensions and binning) -gf or --groupfilter Group files by filter name -gt or --grouptemperature <w> Group files by temperature, with given bandwidth -mg or --minimumgroup <n> Ignore groups with fewer than <n> files -od or --outputdirectory <d> Directory to receive grouped master files Examples: MasterFlatMaker --noprecal *.fits MasterFlatMaker -p 100 -s 2.0 *.fits MasterFlatMaker -a ./bias-library -ar -s 2.0 -gs -gt 10 -od ./output-directory ./data/*.fits