View Full Version : Calibrating Calcu-Light XP

16-Jun-2016, 06:33
My Calcu-Light XP was reading one and two thirds stops under so I thought I have nothing to lose by opening it up. I tested each of the pots and found the one that set up the calibration. It's a simple tweak and I'm now back in sync with my Pentax Spotmeter.

You have to
Take the battery cover off and undo the screws.
Put the cover back on the battery cover with batteries still inside
Peel back the rear cover (glued on) try not to crease it, a smooth bend should be OK
Undo the two screws underneath the cover.

You should be able to access the blue pot with a brass screwhead that is at the bottom of the meter (there are four. Top left and top right and middle left. You want the bottom right one (see pictures).

Turn anticlockwise to increase your reading
Turn clockwise to decrease your reading

It takes about 2 or possibly three turns for a single number change (which is a third of a stop).


17-Jun-2016, 22:21
Hi Tim,

Thanks for posting and documenting this so nicely. I have the exact same Calcu-light XP from years back and noticed (when I recently took it out if storage) that it was 1 stop under. I've been compensating by adjusting the ISO setting, but very glad to know the fix.

Did you determine what the other pots control ?



18-Jun-2016, 04:38
My Uncle keeps looking for one of these. His was stolen a few years a go and he still mourns the loss.
Most sensitive light meter around as it will get readings from 1/4 moon at night.