I have been wanting to mount a 203mm Ektar in a modern Copal 1 shutter for some time now and just assumed that adapters would have to be machined to accomplish this. Fortunately, the lens I had was mounted in a GRAPHIC branded Synchro-Compur 1 shutter and upon removing the front and rear groups, discovered that it would screw directly into a Copal 1 shutter I had sitting around from another project. Of course I had to make certain that the front/rear spacing was the same and so I measured the thickness of the mounted lens with my caliper. I got 35.4mm with the Compur set up and much to my amazement, got the same thickness when mounted in the Copal. Great! No machining or shims needed. All I needed to do now was to make some aperture scales.
I removed the two scales which were marked for a 210 f5.6 lens and applied some white flat back tape which I then trimmed carefully with an x-acto knife. I then reattached the top scale.
I first needed to make some light measurements with the old shutter. I remounted the lens in the Compur and installed in my view camera and aimed it at a softlight. Even a way out of focus setting of the camera resulted in a mottled, uneven illumination of the ground glass, so I fabricated an extreme diffusion filter out of frosted drafting film, cut to fit a filter adapter. That did the trick. So then I got out my Pentax analog spot meter as that one has a scale marked in 1/3 stops. Much to my disappointment, the readings I got were unreliable as it was difficult to center the meter against the ground glass. Undeterred, I thought perhaps an old Gossen Luna-Pro F I had with an accessory fiber optic probe might work better. I got out the Gossen and discovered the battery was dead. In the process of trying to remove the 9v battery clip, I managed to snap one of the connectors off. So changing direction, I got out my soldering station and a spare 9v battery clip and did a transplant. So now the Gossen works with a fresh battery and I was all set to make my measurements. The fiber optic probe appeared to work very well and the Gossen's scale was marked in 1/3 stop increments, so I was able to make some repeatable measurements. I decided to use f22 as my starting point as that would be the aperture I would most likely use with this lens most of the time. I set the Compur to f22 and took a measurement. I checked the other apertures and much to my satisfaction, the meter tracked them perfectly.
I remounted the lens in the new Copal shutter and without changing the setting on my meter, I was able to find an aperture that gave me the same reading as f22 on the Compur shutter. I marked that spot with a .3mm mechanical pencil and proceeded to go up and down the scale marking all the other aperture settings, using the meter and probe to confirm the incremental changes. I then removed the aperture scale and inked in the lines with a 00 reservoir pen from one of my many Leroy lettering sets. As long as I was at it, I figured I would letter in the apertures with a size 60 Leroy template. Once I had one scale done, I remounted it as well as the second scale and simply transferred the info to the blank scale using the marked scale as a guide. I then removed the second scale, inked it in and reinstalled on the shutter. Not as fancy as an engraved scale, but a lot cheaper. I now have one of my favorite lenses mounted in a modern reliable shutter. Please forgive the iPhone photos.
Reply With Quote
Bookmarks