View Full Version : Derogy Ortho Periscope

21-Apr-2011, 00:10
I am looking for some french lens expert.
I found a Derogy Ortho Periscope lens of about 450mm focal. The lens is not very big, but the diameter of the front lens is more than 7cm. There is a slot for waterhouse stops.
I have been looking for informations for a while, but i found almost nothing on the web.
Even the VadeMecum barely reports the existence of the lens (no focal lengths, no optical scheme).
I know what a "periscopic" lens is, but i guess that the word was used by different makers, and maybe in different contexts.

If somebody knows the optic, is it of some interest only as a collector's item?
I mean, is it just another rapid rectilinear look-alike, or does it have a peculiar photographic signature?

Unfortunately there is very little documentation about french LF lenses.
There is an exception: the line of Boyer products, with the very informative web pages by Bertrando/Fromm.
Then there is something about Berthiot and Krauss (that was a Zeiss licensee), but when i tried to find something about smaller brands, i found very little. Sometimes the VadeMecum comes to the rescue, but i found very little, when i looked for infos about Roussel lenses.
It's a true pity. The Roussel example i own, a 210mm f/4.5 Stylor, is of very high craftmanship. The quality of the barrel is more than good, with two protruding pins on the diaphragm ring (in the fashion of an Universal Heliar), with a perfectly circular iris hole, and with an overall feeling of a superior build/assembly level.
Maybe it will perform very poorly... who knows. I have just cleaned the lens, so i had no time to perform any test.
But i have been very impressed when i had to disassemble the objective for cleaning. No hype, but it's not just another anonymous Tessar clone for mass production.
Now i see french vintage lenses with a lot more interest. For example i have just seen a big Krauss Tessar on the bay. From the pictures it looks very well made as well.
Then i saw the Derogy... and i came here for advice :)

have fun


21-Apr-2011, 05:49
Just here: http://www.largeformatphotography.info/forum/showthread.php?t=74599
I think i know your Derogy...
And i think you should look for a Derogy petzval, not that Periscope.

Steven Tribe
21-Apr-2011, 11:40
Note that the 500mm Krauss Tessar weighs well over 2 kilos and the item listing you mentioned is without the very necessary flange! They were produced for the reproduction trades with big static camera. They have been mentioned here before and I have the same lens a few thousand numbers earlier. Krauss have always been identified with build/glass quality - especialy their Goerz licensed products.
I reckon the DOP is something like the Rodenstock Bistigmatic. French sites show the DOP as a standard lens on detective/falling plate type cameras - but there is no sign of the bigger sizes.