I've posted at length about getting my OM-1 and FTb cameras to match my spot meter, after modifying the circuits to use a 1.55v battery, and re-calibrating the meters in each. Both are working perfectly now.
Made me get curious about my other meters, since I actually have a fair number of 35mm cameras in the rotation. So I started testing them all tonight using the same method with a relatively high-CRI LED panel set to 5600k and various brightness levels.
Baseline against which all other meters were compared was my Reveni Labs Spot Meter. The FTb and OM-1 match it exactly since I recently worked on them. The AT-1 was off by 1/2 a stop. Hopefully I can tweak that a hair, but I probably wouldn't hesitate to use it for B&W film at least. The XA was off by 1/2 a stop. I don't intend to ever put slide film through that camera, so that difference is within an acceptable tolerance for me. The AE-1 meter is being weird since the last time I used it. That camera currently has all the light seals scraped out of it and is waiting on new ones to get it back in the fight. I'll see if I can get the meter working as it should when I next take it apart. It has worked in the past and given me good B&W negatives, but I haven't shot it in over a year due to light leaks. The OM-G was dead on, so near as I could tell - its meter readout only really gives you 1 stop increments to read, but it seemed more or less right on.
Here's the weird one - my Elan II. A couple of years ago, I noticed that the Elan II was spitting out thin negatives, and upon closer investigation of the problem, found the meter to be inexplicably, precisely 1 stop off in all "real world" metering situations. I've been offsetting that error by setting 1-stop slower ISO speed since then with good results. So I expected to see that same error tonight.
Instead what I found was... the meter absolutely will not detect anything when shining it at the LED panel at 12EV. I can be inches away from the panel, wide open at f/1.8, with a 20 second shutter speed, and the meter readout in the viewfinder will still be pegged at "-2" and blinking. If I point it at the extremely dimly lit wall in the room with those same settings, suddenly it swings to the opposite end of the scale, indicating (correctly) that I'm overexposing by more than 2 stops. If I increase the brightness, the meter will wig out and flip back and forth between -2 and +2 with no stops in between. It also seems confused about how brightly to illuminated the green meter readout in the viewfinder, and hops back and forth between them. But at 12EV, it's like that big rectangle of light is completely invisible to the camera. Something about that LED panel just doesn't play nicely with the (already weird) Elan II meter. Very odd.
Made me get curious about my other meters, since I actually have a fair number of 35mm cameras in the rotation. So I started testing them all tonight using the same method with a relatively high-CRI LED panel set to 5600k and various brightness levels.
Baseline against which all other meters were compared was my Reveni Labs Spot Meter. The FTb and OM-1 match it exactly since I recently worked on them. The AT-1 was off by 1/2 a stop. Hopefully I can tweak that a hair, but I probably wouldn't hesitate to use it for B&W film at least. The XA was off by 1/2 a stop. I don't intend to ever put slide film through that camera, so that difference is within an acceptable tolerance for me. The AE-1 meter is being weird since the last time I used it. That camera currently has all the light seals scraped out of it and is waiting on new ones to get it back in the fight. I'll see if I can get the meter working as it should when I next take it apart. It has worked in the past and given me good B&W negatives, but I haven't shot it in over a year due to light leaks. The OM-G was dead on, so near as I could tell - its meter readout only really gives you 1 stop increments to read, but it seemed more or less right on.
Here's the weird one - my Elan II. A couple of years ago, I noticed that the Elan II was spitting out thin negatives, and upon closer investigation of the problem, found the meter to be inexplicably, precisely 1 stop off in all "real world" metering situations. I've been offsetting that error by setting 1-stop slower ISO speed since then with good results. So I expected to see that same error tonight.
Instead what I found was... the meter absolutely will not detect anything when shining it at the LED panel at 12EV. I can be inches away from the panel, wide open at f/1.8, with a 20 second shutter speed, and the meter readout in the viewfinder will still be pegged at "-2" and blinking. If I point it at the extremely dimly lit wall in the room with those same settings, suddenly it swings to the opposite end of the scale, indicating (correctly) that I'm overexposing by more than 2 stops. If I increase the brightness, the meter will wig out and flip back and forth between -2 and +2 with no stops in between. It also seems confused about how brightly to illuminated the green meter readout in the viewfinder, and hops back and forth between them. But at 12EV, it's like that big rectangle of light is completely invisible to the camera. Something about that LED panel just doesn't play nicely with the (already weird) Elan II meter. Very odd.