Helen B said:
You could always check it in full sunlight, when the 'sunny 16' rule should apply (at f/16, the indicated shutter speed should be about equal to the reciprocal of the ISO film speed, eg 1/125 for ISO 100 film).
The one thing that kinda bothers me is that there doesn't seem to be any convenient way of comparing an in-camera light meter to a truly known standard. Everybody says to use "sunny 16" as a sanity check, and I'm realizing that it's about as good a test as you can get without resorting to laboratory grade equipment.
I recently recalibrated my QL17 GIII so it would take ISO1600 film, and lacking anything else, I used the exposure of the Pentax K1000 to compare with. It seems to expose properly in both low and high light situations.
The best way is to calibrate the meter to the camera by shooting a test to find the best film speed to set on the camera.
Actually, I think I'm realizing that the best test is with film under the situations you're likely to shoot.
My last "sanity check" roll was some normal and high-contrast (white rocks along a railroad and shadows under the trees) scenes, with 5 frames each, one as the meter said, then 1 and 2 stops over and 1 and 2 stops under.
It gives a good warm fuzzy feeling that the meter is close enough to take real-world photos, but something kinda nags at me that it's not really traceable to any standard.
What''s kind of eye opening is that on some normal contrast scenes, there's really not that much difference between the normal, and +/- 1 stop frames. The modern color negative film (Fuji 200 in this case) really does have some good latitude in it.
Oh well ...