Sample of measuring focal-plane shutter times

For measuring camera shutter speeds, I bought a camera shutter speed meter on Ebay.com in 2019 (its full English name is "Camera shutter and curtain tester for speeds up to 1/8000th with light source" and link to it is still there at time of writing this in February 2023: VFMoto tester, but I don't know how long it will be there yet). It is sold and probably manufactured by Mr. Vasile Florin, Bucuresti, Romania. Because the way he sells it is designed to measure any kind of central shutter and for slit shutters it is only for 35 mm cameras, so in order to measure 6x6 shutter I had to make both illumination and sensor for that size. The 35mm film sensor measures about 29.4 mm in width at distance between beginning and end of run (it has three sensors, for measuring at beginning, center and end of run of curtain / the shutter blades), which is not enough for a 6x6 format, it would not measure actual beginning and end of run. Measuring of my Pentacon six looked something like this:

   Shutter tester can upload measured data to SD card, so I made a program in MS Excel (some people call it a macro) to evaluate times and other shutter parameters, because as you can see in second photo, output from tester although tells you something about the shutter, but firstly you need to understand it, and secondly it is far from everything.

A more detailed explanation of program, including possibility of downloading it, can be found here in programs section: Measuring of focal-plane shutter

Description of 6x6 sensor and lighting is here in section Praktisix / Pentacon six: Instructions for building 6x6 sensor and light