Don’t know much about this lens, since the only markings are ‘Darlot Paris’ and ‘Made in France.’ The back focus distance measures 8.5 inches. We were told this is probably an 1870-90 Darlot ‘Petzval’ portrait lens. The lens barrel is 2 inches in diameter and the length, minus the front shade is 3.5 inches. The barrel is in nice shape, possibly refinished. The glass is good considering its age, with some marks, no major chips or blemishes, probably plenty usable. The lens is thread-mounted directly into a 110x110mm Canham metal lens board (no flange). There are no lens caps. The Canham lens board is included.
A little more information: This is a projection lens. Has no f Stops or Waterhouse Stops.
We mounted the lens on a 5×7 camera. Here is what we found;
Focal Length @ infinity (lens center to GG) = 6”
Glass Diameter = 1.58”
Apparent f = 3.79 I would call it an f4.0
Measured Image Circle = 5”
(The full diagonal of 4×5 would require 6.4”)
This lens would not cover 4×5 at infinity.
The focus mount diameter is 2.18”
Would say the thread mount is about 55mm
The barrel of the lens is, w/o mount 2.07”
Front to rear glass to glass, about 3.02”
Barrel, front to back, w/o hood 3.51”
Total front to back w/hood 4.40”
