Model: L3 (mk 1)
Price (new): $16.95
Cell type: Selenium
Measure type: reflectance
Argus made a variety of cameras over the years, almost all of them manual-set, yet didn't do much with meters. They sold a couple here and there, but it wasn't until the late 50s that they began seriously branding their own.
Later, Argus sold a number of meters, including four with the L3 designation. According to the Argus Collector's Group, there is no special marking on the meters to differentiate them, so the "Mark 1, Mark 2..." designations are my own.
This is a Mark 1, the first of this series. It's actually made by Metrawatt of Germany, and it's the identical twin of my Horvex 2. The only difference is the name and model scribed on the calculator dial, and the case color (black here, the Horvex is creamy-white). It also takes the booster cell accessory, a long-time Horvex feature.
How to use it: on the outer dial, at the bottom, there's a small piece that has two arrows and the plug-in-accessory icon. On each there's a bent tab. Use these tabs to push and rotate it. That lets you set the film speed in the windows on the inner dial. The left window is for the Weston scale, the right window is for the ASA scale, and the bottom window is for DIN.
Once you have your film speed set, aim the meter at your subject and look for the needle in the bottom window. Rotate the outer ring until the big arrow is pointing to the needle. You want to make sure you follow the path to the needle, don't just point directly to it; you see those alternating black and bare-metal strips? Those are the paths. It's important to do this because the calculator dial scale is longer than the meter face so you can't just match the pointers.
Once you do that, you can read the speed/aperture combinations at the top.