Thanks, nicely done. This lens looks like mine.towolf wrote:... this pretty much confirms ~ 1.25mm.
Just look at the entrance to the lens. If it were f/2 then the pupil would have to be 2mm diameter. It is obviously much smaller than that. I measure 1.25mm using a 10x reticle.towolf wrote:How confident are you about the aperture F-number of 3.2? Another user here had estimated f/2.