I need a spot meter and was recently given a Pentax Spotmeter V. Though this originally used three mercury G-13 cells, there are alternative batteries. But I have heard people say that as the batteries discharge, that accuracy falls off. So, one has to constantly test it for accuracy. The frequent suggestion was that it was not worth the trouble and that it was better to get a digital spot meter. What do you think?
I have that exact meter, and it's pretty much perfect in every way. It is the model Ansel Adams designed his Zone System with. I don't really use the zone system, more like my own basic interpretation of it, and the analogue display makes it so easy.
It uses standard LR44 or SR44 button cells, and has a built-in battery level check.
LR44 batteries are as cheap as chips, SR44 batteries are better and only cost slightly more. I replace the batteries around once per year at a cost of about £2 ($2.50). It takes 1 minute.
The digital version is much more expensive and gives you nothing more. Light is a linear, analogue, medium. Linear, analogue, light meters are just... well... better than digital! There, I said it.