FFD Adjustment hints

[Manuel Wenger]

It´s been i while since i did it on a 35mm camera with shims, but
just as a general question.

Lets say you put on your 14mm lens to adjust the FFD set you distance to 100cm put on your collimated lens and measure that you get the right focus at a distance of 104cm (lens is set to 1m) just the camera is moved until it´s a sharp image.

Is there a indication if i need to add or remove shims and in which aprox. thikness ??

thanks
best regards
Manuel

 

[Jacek Zakowicz]

You have a very sharp eye

You have a very sharp eye

It´s been i while since i did it on a 35mm camera with shims, but
just as a general question.

Lets say you put on your 14mm lens to adjust the FFD set you distance to 100cm put on your collimated lens and measure that you get the right focus at a distance of 104cm (lens is set to 1m) just the camera is moved until it´s a sharp image.

Is there a indication if i need to add or remove shims and in which aprox. thikness ??

thanks
best regards
Manuel

You have some sharp vision to see the difference between 100cm and 104cm on 14mm lens. Much better then mine.....
Anyway I would estimate that you need to remove about .002mm(!) to .005mm to be in focus.
Jacek

 

[Manuel Wenger]

Jacek, the numbers where just a random pick, and not a very feasible one
What i wanted to get as a result is (and I hope I´m right)

If your lens is set to 1m and the right focus is further away, FFD is 52+ mm, so shims have to be removed.
If your lens is set to 1m and the right focus is closer, FFD is 52- mm, so shims have to be added.

hope i got it right
thanks
Manuel