Please help to determine the French lens maker.

[photojournalism]

Hello!
Has anybody know the French lens maker named DY? The lens is engraved "Brevet d Invention DY Paris". This is a convertible Petzval-type lens, each element mounted by bayonet and the front achromatic doublet can be used as a landscape lens. Rack and pinion mechanism is present, so it's an earliest Petzval lens, as I can estimate. The place for washer stops is present too. Estimated focal length is 220 mm and wide open approx. 4. Any information will be helpful, thanks.

[Steven Tribe]

Derogy, Derogy or Derogy!
Letters and Bayonet systems.
But will check VM so I havn't made a mistake.

The "place for washer stops" looks like it was the mount for additional central lenses, both + or -, which could change the focal length.
VM confirms what I said. In fact it has quite an extensive description. No mention of the DY abbreviation - these have no serial number, that came later!

[photojournalism]

Thank you Steven! Of course DerogY, I'm so stupid.

[Steven Tribe]

Please, please post lots of detailed photos, if this is yours, as it will be of interest to us who have never seen one - or have who the other later types of bayonet Petzval caskets/convertibles!

[photojournalism]

just a minute

[photojournalism]

here are photos:

69569

[photojournalism]

close-up

69570

[photojournalism]

69571

[Steven Tribe]

Some pretty unique brass work here. Is the "ring" to support extra disc stops/lenses in the middle? Screw or also bayonet?
The middle lenses were also achromats according to VM lens sketch (Der 01) mounted in front of the central stop.

[photojournalism]

Yes, the ring holds the diaphragm disc, but simply by press, without any screw or bayonet.

[CCHarrison]

and thar she blows on ebay http://www.ebay.com/itm/BRASS-LENS-French-Petzval-convertible-Landscape-Earliest-Derogy-Paris-220mm-f-4-/120871334686?pt=Camera_Lenses&hash=item1c247e331e

[Steven Tribe]

Lets hope he buys a copy of the Lens VM from CC with his income so he can do his own research/guesswork next time!

[photojournalism]

P.S.
But slot for diaphragm disc also has a bayonet mount, exactly for additional lens element, I suppose.

[photojournalism]

and thar she blows on ebay http://www.ebay.com/itm/BRASS-LENS-French-Petzval-convertible-Landscape-Earliest-Derogy-Paris-220mm-f-4-/120871334686?pt=Camera_Lenses&hash=item1c247e331e

yes, I just list it )

[photojournalism]

Lets hope he buys a copy of the Lens VM from CC with his income so he can do his own research/guesswork next time!

If you'll be so kind to tell me, where I can buy VM, I'll be happy to do it, here in Russia no information about old lenses at all. And I promise, will not ask questions here)

[Steven Tribe]

CCHarrison has the distributing rights for VM. Send him a personal message (PM) or go into his website where is information at the bottom I think.
Questions are always welcome - especialy about interesting items with verdigris - but perhaps you could be a bit more open about your "objectives" next time!

[goamules]

and thar she blows on ebay http://www.ebay.com/itm/BRASS-LENS-French-Petzval-convertible-Landscape-Earliest-Derogy-Paris-220mm-f-4-/120871334686?pt=Camera_Lenses&hash=item1c247e331e

Bwah-ha-ha-ha! Too funny Dan.

[photojournalism]

Bwah-ha-ha-ha! Too funny Dan.

Nothing to funny))), I'm glad to help everyone to tests old lenses by shooting cats, dogs, bottles, family members, etc., and sell them for $20, but I can't, the shipping from Russia is too expensive - around $100 to US and auction site doesn't understand this high cost for shipping, so I'm forced to list it with "Free shipping" option.

[goamules]

Hey, I didn't mean anything about you selling the lens, that's not a problem, and your price seems very reasonable. I was just laughing at Dan using an old whaling term; the 18th century sailors would say that when they sighted a whale off in the distance. Kind of like "Tallyho" for the Brits. Good luck on your sale for a very nice looking lens.

[photojournalism]

Thanks, and I'm sorry, my English is not so good to understand all nuances.

[Two23]

What decade would this likely be from? I'm guessing 1850s?


Kent in SD

[Steven Tribe]

Probably is (1850's), but VM has the usual "holes" as with most foreign makers!
It could be that the lens is complete as it was when it was sold and that the modifying central bayonet lenses were extras that could be bought later. Or, perhaps, the very first casket set? Jamin had something similar - as demonstrated by Eddie recently.