|Darlot Pill Box Meniscus lens, circa 1860-1880, about 180mm|
A. Darlot was a French optical company, founded in the 1850s as Jamin-Darlot in Paris. In 1860 it became Darlot. It made camera lenses, marked "Darlot, Opticien" or "Darlot Paris" and the initials "AD" of A. Darlot, the letters crossed as logo. B.F. & Co. refers to Benjamin French & Company, who were the sole U.S. Importers of Darlot lenses for many years.
This lens is a Pill Box simple meniscus landscape lens, which Darlot manufactured from about 1860 to about 1880. This lens is probably from the latter production.
The Pill Box design uses diaphram washers held in by a retaining mechanism, allowing the user to change washers to stop the lens down. Invariably, only the installed washer has survived. However, pictorial usage of such lenses dictated that the entire end cap be removed, so that the spherical distortion could be appreciated for its diffusion effects. My copy of this lens has one washer stop, which gives me the following apertures (roughly estimated):
- With the end cap removed: f/5
- End cap on, no washer: f/11
- Washer installed: f/20
Here are some example images:
|Washer installed-fully stopped down|
|Retaining cap removed- wide open|
|six image stitched- wide open lens- CameraFusion back|