If the file is not in the current directory, include the file path in this file name.
When IM_INPUT_FITS is set to a file, all of the control parameters are set as they were when the file was made. You are not allowed to change any control parameter. Info parameters are filled in from the file (either all of the info parameters, or just a few depending on the setting of USE_ALL_INFO_PARAMS).
To resume using the raw files as input, set IM_INPUT_FITS to a blank, or set the IM_ALLOW_REPROCESS parameter.