cyberjunkie
11-Nov-2010, 19:17
Hi.
I found a cheap long focus lens, for which i have found absolutely no infos.
It's a L. Kamm & Co. London 17in (430mm) cylindrical lens (s/n: 59x), without an iris, and without a fitting thread.
The vendor told me that the lens has a "soft focus" character, and that probably will cover 8x10.
As you can see from the pictures, it comes with an extension tube (50mm length), whose use is not clear. My first guess was that it was probably meant to alter the distance of the two optical cells, modifying the optimization of the objective, but when i looked at the pictures with more attention, i saw that the extension tube should have two female threads, so it's very likely that the use was another.
Probably the brand engraved on the barrel comes from a vendor, and not from the actual maker of the lens, because the VadeMecum doesn't mention anything with this name. Being a UK brand, it's very likely that, if there is no reference on the VadeMecum, it was not a true lensmaker.
The barrel is perfectly cylindrical, with no traces of a rack for a focusing barrel, and with no way to attach it to a lensboard. So my personal guess is that it could have been a projection lens, as it's shaped as some modern lenses for trasparencies projectors.
The lens is still on its way, so i have no first hand infos about the optical project, but i don't think it could be a Petzval, as it's fairly small for a 17in lens. I don't know if there were Petzvals of limited speed, that would be compatible with the size of the lens, but i don't see any use for a slow projection Petzval!
The measurements are:
* front and rear elements - width 52mm
* the total length is 83mm
Any clue?
EDIT:
after some more googling, i found an interesting link about L. Kamm:
http://www.victorian-cinema.net/kamm.htm
After all, probably my guess was not too far from truth: he made a special cine camera, and later cine projectors and graphic arts cameras.
have fun
CJ
I found a cheap long focus lens, for which i have found absolutely no infos.
It's a L. Kamm & Co. London 17in (430mm) cylindrical lens (s/n: 59x), without an iris, and without a fitting thread.
The vendor told me that the lens has a "soft focus" character, and that probably will cover 8x10.
As you can see from the pictures, it comes with an extension tube (50mm length), whose use is not clear. My first guess was that it was probably meant to alter the distance of the two optical cells, modifying the optimization of the objective, but when i looked at the pictures with more attention, i saw that the extension tube should have two female threads, so it's very likely that the use was another.
Probably the brand engraved on the barrel comes from a vendor, and not from the actual maker of the lens, because the VadeMecum doesn't mention anything with this name. Being a UK brand, it's very likely that, if there is no reference on the VadeMecum, it was not a true lensmaker.
The barrel is perfectly cylindrical, with no traces of a rack for a focusing barrel, and with no way to attach it to a lensboard. So my personal guess is that it could have been a projection lens, as it's shaped as some modern lenses for trasparencies projectors.
The lens is still on its way, so i have no first hand infos about the optical project, but i don't think it could be a Petzval, as it's fairly small for a 17in lens. I don't know if there were Petzvals of limited speed, that would be compatible with the size of the lens, but i don't see any use for a slow projection Petzval!
The measurements are:
* front and rear elements - width 52mm
* the total length is 83mm
Any clue?
EDIT:
after some more googling, i found an interesting link about L. Kamm:
http://www.victorian-cinema.net/kamm.htm
After all, probably my guess was not too far from truth: he made a special cine camera, and later cine projectors and graphic arts cameras.
have fun
CJ