Another "can anyone identify this lens" thread (Darlot)

My father was apparently rooting around in their basement and found this in a box along with a Brownie Hawkeye thinks was his dad's. Zero idea where this one would have come from, though, since there's no other photo gear anywhere near this old.

There's some info out there about Darlot and the BF & Co importer, but I haven't seen any images that look like this particular lens. I can't imagine it'd be much use since it's apparently extremely hazy and you can see the damage to the front element, but it's still a pretty nifty thing to stumble upon!

it’s probably cleanable. Do you have the Waterhouse stops too?

bdial said:

it’s probably cleanable. Do you have the Waterhouse stops too?

Click to expand...

No such luck! That'll be an interesting bridge to cross should I ever come to it.

I did find this: https://www.antiquecameras.net/images/800_darlot17.jpg

That 'single-view' lens lithograph definitely looks a lot like it, though it has rotating stops. Maybe mine is an older version of the same model? I'll have to measure the diameter when I get my hands on it.

According to A lens Collectors Vade Mecum Darlot were reported marked D.F.& Co. as an early Daguerre type lens.
Meniscus around 1860 had a focus knob; Triple ; Wide Angle Hemispherical; Rapid hemispherical; 1890; Darlot Portrait 1870 onward. There are several other types in the later years, 1887 onward.
A 55,xxx serial number was probably a RR made in the 1890's; a 16, xxx as a 1894 Achromatic f11 used on a 1897 Tourtin camera.
Rochester Optical Company was listing Darlot lens by 1899.
http://piercevaubel.com/cam/catalogsrochester.htm

By mounting the lens of a fixed board, pointing it at a bright light source (infinity will be best) with detail, positioning a white board behind the lens and moving it until the image is in sharpest focus then measuring from the waterhouse stop slot to the board will give the lens focal length, measuring the aperture opening then dividing the focal length by the aperture diameter will give its wide open f stop.

Off-hand my guess would be it's a periscope-type lens, i.e. two single meniscus? A RR-type would be longer, but as a periscope-type is cheaper they may have decided to save on the brass tubing? From the curvatures certainly either a RR or a periscope, most likely the last. Just my two bits, of course.

Alright, finally got my hands on it, and man was it dirty. I disassembled it and cleaned it as well as I could but it's still plenty rough. There was also a dead insect inside thanks to the empty stop slot, which is a new one on me.

Judging by my extremely scientific testing (i.e. mounting it in a piece of cardboard box and putting it on my press camera), it seems to be roughly 150mm and f/6. Possibly has a lot of coverage, too. Here's a shot using the "palm of hand" shutter method (which is really practical when you also have to pull out the dark slide) and hastily botched development, cropped because my camera-scanning rig won't get high enough to take in the whole 4x5 frame without stitching:

It's not gonna win any IQ awards, but it's a pretty cool thing to have! I'm gonna go ahead and imagine that my

Nice find.

I've two lenses with the B.F. & Co engravings, one is a little Petzval and and the other is a big pill box landscape lens which also bears the engraving of Darlot.
B.F. & Co means Benjamin French of Boston. Here's some info:

http://historiccamera.com/cgi-bin/librarium2/pm.cgi?action=app_display&app=datasheet&app_id=1665

https://www.largeformatcameras.net/picture.php?/223/category/83

my B.F. Petzval:

Petzval - Benjamin French / Boston