My 3,5F had sharpness issues when I bought it, so I sent it back to the camera store and they let their Rollei specialist fix it. When it came back the focus was spot on. I've had 30 or more Rollei TLR's over the years (and still own 15-20) and the 3,5F with Planar beats them all when we talk about sharpness. I still love the Tessar and Triotar for their own personalities though.