Matching lensboard to various shuttersgreenspun.com : LUSENET : Large format photography : One Thread
Could anyone explain to me the relationship between lensboards and the various types of shutters mounted on lenses. For instance if your lens has a Copal #0 shutter, do you need to make sure that your lensboard will fit a #0 shutter? And do you simply purchase a variety of lensboards to fit the various shutters or will any lensboard accept any type of shutter? Thank you!
-- Michael Krause (firstname.lastname@example.org), September 10, 2001
Lensboards have holes drilled in them to accept a particular size shutter (e.g. the hole for a Copal 0 shutter is a particular diameter, the hole for a Copal 1 shutter is a larger diameter, the hole for a Copal 3 shutter is a still larger diameter). A lensboard drilled for a Copal 0 won't accept a Copal 1 or 3 shutter, etc. etc. I think most people just buy a lensboard that is drilled for whatever size lens they are going to use it with (or they buy undrilled lensboards and then do the drilling themselves). If you're buying a camera that comes with a lensboard but no lens, you need to know which shutter the lensboard was originally drilled for. In the good old days there were lots of different shutters in lots of different sizes and the numbers didn't necessarily correspond (e.g. a lensboard drilled for an Ilex #4 shutter wouldn't necessarily accept a Betax #4 shutter). A hole that is too small for one shutter size can obviously be drilled larger to accept a larger shutter size. There also are people (e.g. Steve Grimes, Ken Hough) who can modify a larger hole size to fit a smaller shutter size.
-- Brian Ellis (email@example.com), September 10, 2001.
Brian: Thank you for the information . . . I gather that the hole diameter will be determined by the thread diameter of the particular shutter, which fits through the hole in the lensboard? Could a pair of calipers be used to determine the hole size and then, the only problem would be figuring out how to cut a hole to that size? Also, would 1/8" sheet aluminum be a good material from which to make a lensboard? Anyone have input on this? Thanks! Mike
-- Michael Krause (firstname.lastname@example.org), September 10, 2001.
Hello, The aluminum will work if you can get black paint to stick to it. It might if you sand it first real good. Or if you can have it anodized. The easiest thing for me is to get aircraft plywood from the hobby stores and cut to size and paint with flat black paint. I've made most of my lensboards for my technika, agfa, and burk and james cameras with this plywood.
-- David Vickery (email@example.com), September 10, 2001.
I second David's suggestion for model airplane plywood for lensboards. The plywood is 5 or 7 layers of thin veneer, very strong, ridged but easy to work. Aluminum works fine, just a little more work. To prepare aluminum for painting, use a primer of zinc chromate. The aluminum needs to be thoroughly cleaned and free of oil. Regards,
-- Doug Paramore (firstname.lastname@example.org), September 10, 2001.
I've made 2 lensboards for my Linhof Kardan using 1/8" sheet aluminum backed with black felt. The felt is affixed with 3M Super 77 spray adhesive and both makes it light tight and eliminates the chance of internal reflections. I have the dimensions all worked out so that all I have to do is cut out the blank on a sliding compound miter saw (please note, a carbide tipped blade is a must), round the corners to fit, cut the right sized hole, and affix the felt. Voila, a lensboard.
-- David Munson (email@example.com), September 10, 2001.
With regard to your query about the size for the hole ....
Measure the smaller external diameter of the stepped edge of the capstan (jamb nut). That ring must sit snugly against the rear of the lens panel with the larger diameter step doing the gripping.
Cheers ... WG
-- Walter Glover (firstname.lastname@example.org), September 10, 2001.