Files do get pretty big. I either shoot in, or convert to small jpegs before the stitching though. With that many shots, even using 1024's results in a many megapixel file.
Nick, if you google "brenizer method" you'll find more than you ever wanted to know. Basically though, it's a way to get shots with a DSLR, even my crop body 70D, that emulate what would normally only be possible using medium format. In the one above with 55 shots, I was using an 85mm at f/1.4 and standing close enough that I actually needed more than one shot just to cover the kids. Hence so many shots - with plenty of overlap - to get that wide shot. The result is something equivalent to using a 30mm f/.4 on a FF or something nutty like that. I think you can actually find calculators online to show exactly what the fictional lens equivalent would be. But the point being, there is no such lens, especially not on a crop body DSLR - but by stitching panos, you can get the same wide angle w/shallow DOF.
- DAA