Back Focus Problems - Progressive Eyeglasses Impact on Focusing?

[Lamar]

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?

 

[bernard_L]

Poor vision (eyes, glasses) might prevent you from seeing the "good focus"; but they cannot make a blurred (groung glass) or split (prism) image look like a good focus.

 

[Chan Tran]

Poor vision (eyes, glasses) might prevent you from seeing the "good focus"; but they cannot make a blurred (groung glass) or split (prism) image look like a good focus.

I use progressive eye glasses and I don't have the problem like yours only I can see only a very narrow view so I have to look up and down to see other parts of the screen.

 

[Lamar]

I scanned in a roll of Portra I shot in my Nikon FM at the same football game as the TriX in the F2SB mentioned above was shot. I used the same lenses and took the same style shots over the same period of time. Only missed a couple of frames out of 36 on the FM. It must be something with the F2SB and it must just have started as the rolls prior to that exhibited no issues. Hmmm. Everything on the F2SB looks ok though. I would chalk this up to my own fault and just a bad day but why just the one roll when I'm getting concurrently good results on another body??? Time to burn a test roll I guess.

 

[John Koehrer]

I use progressive eye glasses and I don't have the problem like yours only I can see only a very narrow view so I have to look up and down to see other parts of the screen.

Me too!

 

[2bits]

I also wear progressives. Like Chan Tran, I'm also looking up or down. Luckily my distance vision is good, so I just take them off when doing landscape.