Lethargus
29-May-2019, 13:17
I know Darlots are extremely hard to date, but I'm wondering if anyone has put together (or if we could do it as a community) known dates associated with their marking changes.
I'm aware of the old name pre 1860, followed by both names on 1860-1861 lenses, with 1861+ being the usual "Darlot Paris" seen most often.
Do we know when the crossed AD was added? Or if at any point it stopped being used? Because there are plenty of lenses without the crossed letters. Further, do we know when they stopped putting ink marks on the glass, or if there's any rhyme or reason to the marks on the older glass?
My interest in doing this has been reinvigorated by a recent acquisition. This lens is about 4" long with a cam but no waterhouse stops, so assumed it would be a projection lens triplet or something simple. It's marked "Darlot Paris - Made in France" with no other barrel markings, including no crossed AD. The lens is in great shape, so I assumed early 1900s. However, when I take it apart it's an honest Petzval and has quite a bit of writing that could be "4 N3 515 13 Darlot Paris" on the front lens pair and the larger rear lens matches with "4 515 Darlot Paris." This basically has many conflicting indicators based on what I've managed to collect, but it doesn't look like it's an amalgamation nor repair job.
So can we put rough dates to when Darlot changed their marking practices? I'm especially interested in when the crossed AD was either added or removed because I honestly haven't ruled out this being a very old counterfeit.
I'm aware of the old name pre 1860, followed by both names on 1860-1861 lenses, with 1861+ being the usual "Darlot Paris" seen most often.
Do we know when the crossed AD was added? Or if at any point it stopped being used? Because there are plenty of lenses without the crossed letters. Further, do we know when they stopped putting ink marks on the glass, or if there's any rhyme or reason to the marks on the older glass?
My interest in doing this has been reinvigorated by a recent acquisition. This lens is about 4" long with a cam but no waterhouse stops, so assumed it would be a projection lens triplet or something simple. It's marked "Darlot Paris - Made in France" with no other barrel markings, including no crossed AD. The lens is in great shape, so I assumed early 1900s. However, when I take it apart it's an honest Petzval and has quite a bit of writing that could be "4 N3 515 13 Darlot Paris" on the front lens pair and the larger rear lens matches with "4 515 Darlot Paris." This basically has many conflicting indicators based on what I've managed to collect, but it doesn't look like it's an amalgamation nor repair job.
So can we put rough dates to when Darlot changed their marking practices? I'm especially interested in when the crossed AD was either added or removed because I honestly haven't ruled out this being a very old counterfeit.