I have 4 raw gcal flat field images which I performed gprepare on before using the gsflat task on. Two of the flat field images were taken using a 0.75 arcsecond slit and the other two were taken using a 5.0 arcsecond slit. I have processed the two resolutions separately using gsflat and have in turn created two master flats. Now I am wondering, which of the two master flats should I be using for further processing of my science images? For example, when I want to perform gsreduce, I want to set the flat field correction to yes, and so when I specify the “flatim” parameter which master flat should I use? My guess is the higher resolution 0.75 arcsecond flat but this is also my first reduction and I am very new to this.
Any help is appreciated!