Thanks for the patent number Steven. Sure enough it does say “DRP No 74437” on the brass (you can make this out in the second photo that I posted), so that confirms that it is indeed a Series III lens.

Tony, that’s a great observation regarding the font of the letter “3”. Therefore the large aperture must be either US f/2.8 or f/2.9… both of which would roughly correspond to the f/6.8 that we are familiar with.

When I close the shutter I do see two bright reflections and two dim reflections on the front cell, and when flipped around on the rear cell also – eight reflections total. I can see this with a strong light facing the lens, but with the light off I only see two reflections on each cell.

I’m amazed at how well this lens has held up over the last 110 years. There is only the very faintest hint of discoloration in the cement between the elements. And looking through the lens, the glass looks crystal clear with the exception of two miniscule (pin-prick) air bubbles in the front group. Goerz must have known that we would still want to use these a century later!