I am saving jpeg images to my USB-HDD with
raspistill. It saves an image every 2 seconds and this uses up 1GB in 15 minutes with the fat32 filesystem. I was wondering if the filesystem was ext2, would it save the jpeg images more efficiency(using the least amount of space)?
Although fat has all sorts of problems I don't think this is necessarily one of them. ext2 might offer some improvement, ext4 probably would, but your biggest improvement would be compression and archival. either something like zip or tar.gz or maybe since these are sequential images mpeg
I don't think ext2 would be better than fat32 in this particular case - not in saving the same information in considerably smaller space.