Damaged lenses
I recently acquired a Turner-Reich Gundlack 12" convertible lens in a Betax shutter, which in fact, I bought mainly for the shutter, so I could mount my other 12" Gundlach lens to make it more usable. The lens that came with the shutter is quite damaged: a wide margin of balsam separation round the edges of BOTH front and rear groups, and one of the center adhesive layers in the front group is a network of separation squiggles and lines. You'd look at this lens and think 'Poor thing, you aren't much use anymore, are you?!"
Well, I decided to mount in in the Betax shutter and see just how compromised it is. This photograph is the result. Yes, the negative has suffered some loss of contrast (light dispersion) and maybe softened a bit, but it was a perfectly usable negative!
Click to zoom way in and see the details.
I used a medium yellow filter, so adjusted to give an extra 2 stops: 1/2 second became 4 seconds (reciprocity) exposure at f11.5, using 8x10 inch Ilford HP5+. Negative developed in Pyrocat HD, 10 minutes standard dilution.
Damaged lenses
I recently acquired a Turner-Reich Gundlack 12" convertible lens in a Betax shutter, which in fact, I bought mainly for the shutter, so I could mount my other 12" Gundlach lens to make it more usable. The lens that came with the shutter is quite damaged: a wide margin of balsam separation round the edges of BOTH front and rear groups, and one of the center adhesive layers in the front group is a network of separation squiggles and lines. You'd look at this lens and think 'Poor thing, you aren't much use anymore, are you?!"
Well, I decided to mount in in the Betax shutter and see just how compromised it is. This photograph is the result. Yes, the negative has suffered some loss of contrast (light dispersion) and maybe softened a bit, but it was a perfectly usable negative!
Click to zoom way in and see the details.
I used a medium yellow filter, so adjusted to give an extra 2 stops: 1/2 second became 4 seconds (reciprocity) exposure at f11.5, using 8x10 inch Ilford HP5+. Negative developed in Pyrocat HD, 10 minutes standard dilution.