How to mount a lens to a lensboard?greenspun.com : LUSENET : Large format photography : One Thread
I am starting out in LF. I have a Rodenstock lens and metal lensboard. A Toyo lens wrench is on it's way to me. I am trying to figure out how to put the lens onto the lensboard. I saw a mounting ring (nut) riding on the threads behind the copal shutter. The core of my question is that, since the rear of the lens is larger than the hole on the lensboard, then how do I put the the lens through the hole? Do I need to unscrew the rear part of the lens?
Since I don't have the courage to experiment on this expensive lens. I would like to get some hints here. Thanks a lot in advance.
-- Dai Sieh (email@example.com), March 18, 1998
The lens assembly consists of a front lens component screwed into the front of the shutter, and a rear lens component screwed into the rear of the shutter. Just grasp the outside of the rear barrel and unscrew it, unthread the spanner nut from the shutter, slip the rear end of the shutter into the hole in the lensboard, tighten the nut against the lensboard with the wrench, and screw in the rear lens component. It is not necessary to tighten the latter more than hand tight.
-- Sean Donnelly (firstname.lastname@example.org), March 18, 1998.
I would add only two things to the above description. First, be VERY careful when unscrewing and replacing the rear lens element--the threads are extremely fine and can easily be damaged. Second, you might want to consider having a professional camera repairman do the job for you. While its not really difficult, the possibility of damaging the threads or (even worse) the internal glass surfaces has always made me nervous about doing this myself.
-- Rob Rothman (email@example.com), March 19, 1998.
If you do not have a lens board that has been machined to fit your lens you will either have to do the work yourself or try to find a friend with a small machine shop to help you.
If you are using a metal lensboard, you want the hole enlarged until it is just big enough to fit the mounting threads (the ones that the retaining ring screws on to) Then remove the retaining ring, insert the back of the lens into the hole, line it up so that it looks straight from the front, and thread on and tighten the ring.
If you have a wood lens board you may have a different type of mounting ring with some screw holes around the edge. Here you want to machine the hole so that it just fits the raised locating ridge on the back of the flange. Secure the flange to the board with the proper size wood screws, and thread in the lens.
-- Tony Brent (firstname.lastname@example.org), September 08, 1998.