Germanium diode in F Photomic finders
I have seen a number of web sites and people suggesting the use of a germanium diode to reduce the voltage of alkaline batteries for F photomic finders. I did an experiment, whereby I measured the voltage drop across a germanium diode in series with two LR44 alkaine batteries connected to a FT finder, under different lights from EV5 to EV15. It shown that the voltage drop across the germanium diode is not constant, as it changed with the current through it.

Therefore the use of a germanium diode is not ideal, as it introduces another variable in the circuit. Also, it is wrong to assume a 40 year old Cds meter is still accurate from very dim to very bright lights.

The best solution is to calibrate F photomic finders to use 1.5V batteries without adding a germanium diode.

Furthermore, I don't recommend 1.5V LR44 alkaline or SR44 silver oxide batteries, because they can leak, even when still good. I only recommend 3V lithium batteries, because they don't leak even when dead.