Left:Takumar @ 5.6. Center: Mamiya-Sekor @ 2.8. Right: Takumar @ 3.5. The focus point of all three shots fall very close to the eye of the subject.
Please refer to picture "Montage 1" in this gallery for a comparative evaluation of both lenses. Tje difference between this picture and "Montage 1" lies in the choice of the Takumar shot at f/3.5.