If the focus was good on the DSLRs, I suggest you check the placement of your focus screen on your F-2. Make sure it's correctly seated and your DE or DP1 finder is also firmly seated and locked in place. Also double check the F-2 focus using your 1.4 lens.

If those things don't work try a focusing diopter. I hated to admit it myself, but a while back I was blaming my 500CM when it was my own 20/20 coupled with age-related limitations errr, so-to-speak.