Discussion in 'Large Format' started by david_gardner|6, Dec 14, 2011.
Anybody know 'em?
Hit #1: Linhof board.
Shen-Hao cameras 4x10" or smaller: Linhof type lens board, 96 x 99 mm.
Shen Hao cameras 8x10" or bigger: Sinar type lens board, 139 mm square (adapters available for Linhof size lens boards).
Friedemann: Thanks for the info. What I really needed was the thickness. I've got some 1/4 inch plywood that I need to plane to the correct thickness to make a board. I've got some boards, but they're packed away.
Brian: Thanks for the info. I clicked the link and then clicked the first result, but it gave me completely different info.
Linhof board thickness is exactly 2mm. If you make them yourself (like I did), make them a bit thinner and rounded at the bottom (only at the side facing the camera). This makes the boards slip into position much easier. You'll know what I mean when you put the plain board into the front standard.
Don't know the thickness of Sinar boards, they're a bit complex with different thickness of rim and center area and recessed areas.
Thanks again, Friedemann. Are you talking about metal Linhof boards? I'm pretty sure that my wood Shen Hao boards are between 3/16" and 1/4", probably something like 5-6 mm.
Just to be sure: which lensboard size are we talking about, Linhof or Sinar? What camera do you have?
The metal Linhof size boards (including third party boards) are 2mm thick. Of course you can make them up to 4mm thick, but then you have to machine the boards down to 2mm at top and bottom rims to fit them under the bars which hold the lens in place.
I did it this way: I cut a piece of 2mm plywood to 96 x 99 mm size, then cut another one to 96 x 80 mm, glued them together centered, leaving edges of 2mm thickness at top and bottom, then drilled the lens mounting hole to the appropriate size for Copal 0 or 1 shutters (34 mm for Copal 0, 39mm for Copal 0, if my memory serves me right).
With lensboard thickness more than 4mm, Copal shutters can't be properly mounted.
If you have Sinar size boards with ca 5mm thickness, then they should have a center part which is something like 3.5mm thick. They should also have a thinner rim, something like 2 or 3 mm.
If you have 96 x 99 mm boards with overall 5mm thickness, then something is wrong.
I have a Shen-Hao 4x5.
I like your idea of doing two boards and gluing them together. I never thought of that.
I did more than this: I took a third piece of plywood and cut a circle (size a little smaller than the round opening in the front standard), then cut another hole into the round piece, large enough to mount the retaining ring. I glued this third piece onto the back of the lensboard for additional rigidity and as a light trap. In fact you don't need that trap because the light doesn't travel around corners, but you'll never know... You can make the back ring thicker, of course. I had to do a little grinding to round the edge of the ring, so the board would slide smoothly into the hole of the front standard.
The asymmetric form of the ring is due to the off center location of the lens mounting hole.
Hey that looks pretty nice!
Another way to go is to just plane the front top and bottom down to the correct thickness. But that doesn't look as nice.
What are the screws for? What does the front look like?
The screws are there to fix a Linhof "rapid" cable release socket. The little adapter (next to the tip of the cable release you see in the picture) is needed to fix the cable release to the socket. I push the cable release into the socket from above until it clicks into position, after shooting I pull the red button down and the cable release can be removed. The lensboard you see here does not have the double plywood construction described above. Right now I have only this one lens at hand.
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