Photex/Verito Mystery Lens

[cuypers1807]

A bit of a mystery lens. The barrel says Photex 16 1/2" f/6 in a non functioning studio shutter. When I unscrewed the rear element, I found the 15 in. f/5 Verito branding on both the front and rear elements. I thought all Veritos were f/4 and I haven't seen a 15" version. (I have the 14.5 and 18 in. Veritos) Why would this lens be labeled 16.5 in. f/6?? It looks like two front elements screwed together.
I have found out that Photex is short for the American Photographic Textbook Company out of Scranton, PA.

[Dugan]

That is quite mysterious.
There is no mention of Wollensak engraved on the trim ring.
Two front 15" elements together to make a 16.5"?..
Shouldn't that make for a shorter overall FL?
Maybe it created a symmetrical design, like a Rapid Rectilinear...for use as a process lens.

[Whir-Click]

Are the front and rear cells single elements or cemented doublets? If the latter, then I would posit Wollensak was re-purposing surplus trim ring hardware from the short-lived f/5 Verito, but that there is no optical association between this lens and the Verito.

The lens cell placement, 16.5” focal length with f/6 max aperture, and “view and portrait” phrasing all make me think this is a Versar (Wollensak’s extra-rapid rectilinear) custom engraved for the American Photographic Textbook Company. Identifying both lens cells as doublets would cinch it for me.

Wollensak made the 15” f/5 Verito only in 1911; by 1912 the focal length was changed to 14.5” and the maximum aperture increased to f/4. The lens was engraved “Wollensak - Rochester” on the barrel, but not on the name ring.

[cuypers1807]

Are the front and rear cells single elements or cemented doublets?
The lens cell placement, 16.5” focal length with f/6 max aperture, and “view and portrait” phrasing all make me think this is a Versar (Wollensak’s extra-rapid rectilinear) custom engraved for the American Photographic Textbook Company. Identifying both lens cells as doublets would cinch it for me.

They are to cemented doublets. I believe your Versar suspicions are correct. Didn't realize there was a 15in. f/5 Verito. That part had me confused but what you describe makes sense. I'll get this thing on a board this week and see what it can do. With the seized studio shutter I am stuck shooting wide open for now. Thank you for the help.