dmr
Registered Abuser
For the one GIII, I recalibrated it using the "wrong" 625 cell, including intentionally mis-adjusting it so it will now handle up to 1600 ISO/ASA film. That was a few years ago and since then it's been actually close enough for Kodachrome. It agrees within 1/2 stop or so with the Pentax and the "new" Gossen Super Pilot meter.
For the other GIII I've been using a Wein cell. Good, except you need to remember to re-paste the sticky over the vent hole if you're not going to be using it for a while, else the Wein cell runs down quickly.
For the Mamiya SD I simply use the "wrong" 625 without a recalibration. It's actually very close. I shot a roll of Kodachrome in it, bracketing carefully, and the "middle" one of the three was best most of the time.
For the other GIII I've been using a Wein cell. Good, except you need to remember to re-paste the sticky over the vent hole if you're not going to be using it for a while, else the Wein cell runs down quickly.
For the Mamiya SD I simply use the "wrong" 625 without a recalibration. It's actually very close. I shot a roll of Kodachrome in it, bracketing carefully, and the "middle" one of the three was best most of the time.