OK, here is another odd duck that I cannot find out anything about. I got it with a Calumet C2 outfit and it's in a Copal 3. It is marked as made in Japan, and the only hint at a manufacturer are the initals Y.O. after the made in Japan line. Any idea as to who made it, and is it intended for 8X10, and what kind of covering power.

The way I understand it, these were made under several names and it is thought to be a Congo by Yamasaki Optical. The only thing I was ever able to find out (very sketchy) is that they are an acceptable lens that is either liked or disliked. How's that for vaguery?

Quote:

On 2004-10-09 17:49, disemjg wrote: OK, here is another odd duck that I cannot find out anything about. I got it with a Calumet C2 outfit and it's in a Copal 3. It is marked as made in Japan, and the only hint at a manufacturer are the initals Y.O. after the made in Japan line. Any idea as to who made it, and is it intended for 8X10, and what kind of covering power.

When in doubt, get the answer from the horse's mouth. The horse you want's e-mail address is congo@cosmonet.org and it reads and writes english.

Cheers,

Dan

Could this have been a lens originally intended for photo lithography applications? I remember seeing huge view cameras involved in the photo engraving of half-tone images. This would indicate that this lens is set up for relatively close images, and would cover a large "film" area. Does anyone concur?

I think you're on the right track. These were a process lens but they should be ok for general photography at small aprtures.

Quote:

On 2004-10-11 13:22, Joe Koski wrote: Could this have been a lens originally intended for photo lithography applications? I remember seeing huge view cameras involved in the photo engraving of half-tone images. This would indicate that this lens is set up for relatively close images, and would cover a large "film" area. Does anyone concur?

I don't concur, but thanks for asking. Process lenses are rarely delivered in shutter.

Cheers,

Dan

The lens (according to the congo website) is a Tessar formula and most processing companies gave up the tessar in favor of the dialyte (Artar) type after WWII.

It says it covers 10x12, so 8x10 should be pretty sharp even wide open with no movements.

The oft repeated complaint about the Congo's is quality control. Or the lack of it. If it's a good lens then it's good. The 120mm congo sounds interesting. New the cost isn't much higher then getting a brand new shutter.

If it was a process lens it would only have large coverage at close focussing. Which shouldn't be any different from a normal lens. The problem with quoted process lens coverage is it's stated at something like 1:1 not at infinity. So numbers that look great on paper don't look so good on the camera.

<font size=-1>[ This Message was edited by: Nick on 2004-10-11 19:19 ]</font>