One of the things I have to do is make a conversion chart for the emulsion speeds. On the Master II's, the numbers are Weston values, not ASA. Also, the meter is more than 65 years old, and a preliminary check shows I thing 4 stops difference between the meter and my camera. So, I'm going to read my 18% gray card with my camera and meter then rotate the Weston speed dial to match the aperture/shutter numbers and make a chart for ASA settings for the meter.