Boy you guys just love to overthink things and discuss in circles
In defense of both Graflex and Calumet I'll toss in my experience. Although it's been many years since I tested my shutters...
When I first got the Calumet tester, I tried it on a couple of Speed Graphics with impressive results. Well within factory specs, even before cleaning and lubing. I ran into trouble with the leaf shutters as they were all out of spec and slow at the higher speeds.... Exhaustive research provided the answer. You _never_ measure a leaf shutter at the center of the opening! Now as I said up top, it's been years so I don't remember the exact measurement, but you're supposed to measure a leaf shutter approximately one third out from the center. This will give the true speed of the shutter and is how the factories did their tests and calibrations..........
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