Wollensak in Alphax US Navy Shutter

[Art Liefke]

I have a 210mm Wollensak Raptar f4.5 lens in and Alphax shutter that has "US Navy" on it. The shutter has no f stop markings on it and I was curious as to why this is so. I've marked f stops on it using the aperture diameters of another 210mm lens, but I'm interested in selling the lens, and when I list it, would like to have a reason for this anomaly. Also, is the way that I figured the f stops legitimate?

[Dan Fromm]

The shutter is engraved "Viewlex." Viewlex made slide projectors, tachistoscopes, and lenses. They bought in shutters. Y'r shutter is probably from a tachistoscope; t'scopes don't need diaphragms, hence no need for an aperture scale.