Removing Lens From Synchro Compur Shutter

[Steve Bell]

I'm new to large format photography, and have been given my first lens, a Schneider-Kreuznach Symmar 150m F5.6 in a Synchro Compur shutter. The lens front element has an abrasion about 1mm x 2mm right in its centre. It is the glass that is damaged, not the coating, I can feel its roughness with my finger nail. The lens is currently mounted on a Sina panel.

I have an option to obtain another lens/shutter of the same type, but with a damaged shutter. How easy is it to remove the good lens and add to the good shutter?

The lens can also be configured as an F12 265mm, I think by removing the front element. Can I swap front elements, or are they optically matched to the remainder of the lens?

Any advice on making this lens useable is welcome.

[Ernest Purdum]

If the lenses are identical specification, there is no problem swapping cells. The cells screw right out, just be careful to screw them in gently because the very fine threads are easily damaged. One of our contributors even puts different focal length cells front and rear and is very happy with the results. This is not really surprising since earlier symmetrical lenses (Protar VII, Turner-Reich, and many others) were supplied with differing focal length cells.

[Moe_4073]

Steve, Try shooting a couple of sheets of film with the damaged lens as-is. I've seen some ugly roughed up lenses (and own one or two) that can still produce a good image. You can also try filling in the scratch with black ink to reduce the scratch's light scattering from affecting the image. Cheers,

[Steve Bell]

Ernest, how is the front element removed? I can see a black retaining ring around the glass, with 2 small cut outs on each side. Do I grip this with something like the prongs of a circlip retaining tool and rotate carefully anti clockwise?

Steve Bell

[Dan Fromm]

Steve, Ernest, pardon me for jumping in.

Steve, just grab the barrel and turn it. That black retaining ring holds the shutter's face plate on, don't remove it. If the barrel won't unscrew, press the front of it into a tire's sidewall and turn the shutter.

Cheers,

Dan

[Ernest Purdum]

Dan,

Glad you did. Your comments are always welcome.