File extension question

[Grady Boyce]

I have seen FITS files come with three extensions: *.FTS, *.FITS, *.FIT.

What's the difference and does it matter?

Thanks, GB

[Bob Denny]

It doesn't matter. One program or another will default so it may be inconvenient. Windows has settings for which extension opens in which program by default.

[Grady Boyce]

Thanks. Had a guy trying to tell me science images only had *.FITS as an extension. Didn't make sense to me. Appreciate it. G

[Eric Dose]

Most programs designed for a modern OS and which can read FITS files will read a file with any extension, your woefully misinformed guy notwithstanding. (There's a lot of snobbery out there: "Oh, well, I say, by science I assumed you meant Linux, of course. And do you have any Grey Poupon?")

But many or most FITS-handling programs will write only one extension, and you often don't get to chose which one (looking at you, MaxIm DL).

[Bob Denny]

Maybe he’s using VAX/VMS or a PDP-11.