I shot a roll of film a few weeks back and just developed it to find over half the shots were back focused. This was using an F2SB with several different lenses at wide apertures, 35mm to 200mm. I have not had the issue with this body before and I have never had an issue where so many were out of focus and consistently back focused. Nothing I know of has happened to the body. Was it just me having a bad day? Sometimes I wonder if my progressive lens glasses hamper my ability to focus. Does anyone here know how progressive lenses impact the accuracy of focusing on an SLR? I know when I'm using the viewfinder to focus I have to find the "happy spot" by positioning my eye and glasses lens just right to get a clear image on the focusing screen. I use the split image as well to verify. I've always wondered if, that since there is another piece of glass in the mix, it could cause issues but I just haven't had a problem before. The glasses are not new either, I've had this pair for a year now. Thoughts anyone?