View Full Version : Derogy Portrait lens No. 2 f4? (+ Early protar / Krauss lens?)

19-Aug-2012, 13:33
G'day all!

Today I found (Or bought, rather) an interesting Derogy lens, it's a somewhat newer Derogy lens considering it has a built in aperture with a lever sticking out for adjusting it with a normal f/stop scale (f4 to f22).
On one side is the logo and serial; No 32863, Derogy Fab.T, Brevete Paris & Londres. On the other side is the lens' name and number; a Portrait No. 2. Focal length appears to be around 210mm.
I didn't find it in the vade mecum and I can't unscrew the front lens to find out the optical formula. The rear elements (2) make it look like a petzval. Anyone have any info or user experience with this lens?

I also found a cute little old E. Krauss lens who used to make Zeiss copies for France, but with a very early serial number. It's a 120mm f7.7 'Anastigmat-Zeiss' with a #967 serial. Am I right into thinking this is an early Protar?

With kind regards,

Steven Tribe
19-Aug-2012, 17:10
F7.7 sounds like a "late!" Protar - series VIIa. Just the back element is an excellent longer lens.

Derogy made lots of Petzvals - this is from one of the slower series. Petzvals and many other types could still be bought with just Waterhouse stops until 1900 at least, so an Iris mounted lens could be older than a Waterhouse stop similar . Lenses with irises cost a little more. "Lever sticking out" was the early system before ring adjustment. These are occasionally built into objectives which were originally sold with Waterhouse slots.

19-Aug-2012, 23:53
Thanks! Though if it were a late protar, wouldn't it be labelled as such? Considering the early E. Krauss serial I'd say this was before they started calling the 'Anastigmats' Protars, no?

Man, here I was happy to have a 'fast' f4 petzval, only to find out it's a slow one. :rolleyes: Thanks for the info.

Steven Tribe
20-Aug-2012, 02:19
The F3 Petzvals "fast working - schnell arbeider" are, of course, so big that they only suit studio cameras.

Both Krauss and the patent owner Zeiss were not too good ( actually bl**dy awful) about giving series number. The F value and the engraved focal length gives them away. All the various series of Zeiss anastigmatics were developed in just a few years after 1893. Krauss have a very good reputation for the quality of their licenced products. It is said that Zeiss did not have a big production apparatus in the 1890's, so were quite happy to licence production to Voigtländer, Ross, Krauss etc. etc. Turned out to be a good business model!

21-Aug-2012, 11:47
It's pretty hefty for it's focal length, larger then my Dallmeyer Pentac f2.9 in the same focal length. If the aperture mechanism wasn't in place, it should be able to reach f3, considering it's all inside the barrel and acts as a sort of base aperture / washer stop, the glass quite larger then this inner mechanic stop. If I stop the Pentac down to f4, the resulting aperture blades form about as big an opening as is left on the Derogy.

I see. I know the story of the licensing, and I actually own quite a few Krauss lenses, they're a lot easier to find then their Zeiss counterparts, and quality wise quite impressive. Thanks for all the info. :) Now to find a flange.......