I’ll bet that when you press your camera’s button, you get a crisp photograph. I’ll bet you take it for granted.
There was a time when photographers had to actually know something about exposure to get a good shot. Except on cheap cameras, which fixed exposure for passable photos under most conditions, photographers had to answer two questions correctly: How far away is the subject? How much light is on the scene? Guess wrong and botch the photo. Somewhere along the way, cameras gained the ability to figure these things out. Until then, photographers relied on external tools to help them. One such tool was light meter (sometimes called an exposure meter). When aimed at the subject, it gave information the photographer used to set the camera’s aperture and shutter speed for proper exposure.
My camera collection became a photographica collection not long ago when I found this GE PR-1 Exposure Meter in an antique store. I paid five whole dollars for it.
This meter fits into the palm of my hand. While I wouldn’t call it heavy, it does have surprising heft for its size. The body is plastic, probably Bakelite. The dials might be aluminum. Its heart is a little selenium cell. Selenium has photoelectric properties; that is, light causes it to emit electrons. More light means more electrons. The meter measures this electricity and reports it in a way a photographer can use.
This meter’s usage is actually quite clever:
- Set the film speed. Press the little tab on the black inner dial (it’s at about 7:00 in the photo) and twist until the film speed clicks into the little window above the GE logo.
- Twist the outer dial – counterclockwise in low light, clockwise otherwise – until you see three little pointers (“tines”) pop up.
- Aim the meter at the subject and press and hold the button on the left side. Let go when the needle stops moving. The needle stays in place.
- Twist the outer dial until the center tine lines up with the needle.
- Look at the f stop numbers on the outer dial and the shutter speed values on the inner dial. Set your camera to any matching combination of f stop and shutter speed and you’ll get a properly exposed photograph.
These are just the basic instructions; there’s quite a lot more to know about exposure. That’s why the PR-1 came with a 47-page manual, page 42 of which explains how to use the screw on the back to calibrate the meter.
GE made bazillions of PR-1 meters starting in about 1948. I’m not sure when GE stopped making PR-1s, but I do know they got out of the light-meter business by 1960 as selenium gave way to cadmium sulfide (CdS) and as better cameras increasingly came with onboard light meters.
My PR-1 still registers light with gusto, but I haven’t tried it out yet to see how accurate it is. One day I’ll load up my Kodak Retina Ia or maybe one of my Argus C-3s and take the PR-1 along for some shooting.