unusual Artar-like Goerz 8" f11 process lens

[John Schneider]

I'm now getting around to examining an eBay purchase from a while ago. I'm guessing it probably came out of a process camera of some sort. It's a tiny 8" f11 fixed aperture. The threaded flange is aluminum but the rest looks like brass. I unscrewed the front cell to confirm that it is a two-element, presumably Artar design. The rear group is accessed by unscrewing a retaining ring at the rear with a pin spanner. The rear group is pretty firmly set in place so I haven't tried to remove it, but it's a very thick, cemented construction. The rear surface is plano so it's not a Dagor design but I don't know what it is. A LED test reveals four reflections, equally bright, of which three move in the same direction. Does anybody know more of this lens or its original application?

[Steve Hamley]

John,

No one else has replied, but my guess is that it is a Trigor design. Goerz made them branded as Goerz Trigor, Argyle, and possibly other brands, As far as the curvature goes, do you think the glass is reversed? What does the other side of the rear glass look like, if you can check it through the barrel?

Cheers, Steve

[E. von Hoegh]

John,

No one else has replied, but my guess is that it is a Trigor design. Goerz made them branded as Goerz Trigor, Argyle, and possibly other brands, As far as the curvature goes, do you think the glass is reversed? What does the other side of the rear glass look like, if you can check it through the barrel?

Cheers, Steve

Trigor was a Dagor type, meaning that the front glasses would be a cemented triplet, not two airspaced glasses.

[Steve Hamley]

Yep, maybe missed a ghost? Artars didn't become f/11 until 19"

However, if it is a dialyte, maybe someone cleaned the glass and reversed an element.

Cheers, Steve

[John Schneider]

I have several Trigors and this is nothing like those. The front is an air-spaced dialyte for sure, but the rear looks like one thick, cemented cell (I haven't been able to push it out). Interestingly, the rear surface of the rear element is completely flat, whereas the inner surface is concave like a Dagor. When compared to a R-series (process) Dagor of 8.25" f.l., this lens is both smaller in diameter (as to be expected with the smaller diameter aperture) bot also significantly shorter, implying a different design than the Trigor/process Dagor.