Does "GeoConvert Helper" change my tif to bmp?
GeoConvert Helper doesn't touch any files apart from the bmp and inf files.
At the moment it will copy all files matching the file masks "Area_L*.bmp" and "AreaFSInfo*.inf". As it will not delete any tif files in the destination directory copying the tif files before pressing Start should work.
If it helps i can add a function that copies also tif files matching the file mask "Area_L*.tif from the source to the destination directory.