Pentax Spotmeter Battery

Hi

I have recently acquired a Honeywell/Pentax 1/21 degree spot meter. It takes a 1.3 volt 640-type mercury battery which of course are no longer made. Does anyone have a suggestion for a suitable replacement that will not affect the accuracy or operation of the meter? I've found that there are 1.5 volt alkaline replacements but I'm not sure of their suitability.

Cheers, Bob

I've been using the 1.5v cells in my Spotmeter V for about 10 years with no problems. However I suspect that the situation is similar to Spotmatics, early ones don't read correctly with the 1.5v cells, while the Spotmatic F's and later Pentax cameras have voltage control circuitry and aren't affected.

Contact Pentax themselves, they are very helpful and should be able to give you the correct options for your meter.

Ian