tachihara lens board

[jason_3776]

helllloooo,

so, i have acquireed an old tachihara field camera. i was TOLD it came w/ a copal1 lensboard. wrong... it has a lensboard allright, the problem is it is a solid block of wood. it seems quite thick too, 1/4" ? so... evidently the thickness is not a problem, right ? it seems wrong to have such a thick lensboard, but as long as the lenses fit thru it properly. which is the second issue, do i just mark out my proper size hole & cut away ? & how does a recessed lens board work ? are they just as thick like that ? just seems odd... do i need a recessed board for a 75 & shortest ? enquiring mind wants to know.

[mitch rosen]

Your Tachihara takes Linhof Technika style lensboards. The 1/4 inch thick block of wood will not work. Companies such as Midwest Photo, Adorama, and Badger Graphics, to name a few, have aftermarket lensboards that will work fine in the $30-40 range. These are metal boards which are easier to purchase predrilled unless you feel comfortable doing the machine work yourself. When using boards that are drilled "on center" with your camera you should make use of the "dot" reference mark on your front standard. Boards that are drilled "off center" (fairly common) are lined up with the "L" reference. The Tachihara may focus a 75mm lens at infinity without a recessed lensboard but to allow for reasonable movements a recessed board is recommended by most folks. Recessed boards are expensive so look for something used or check out the Shen Hao recessed lensboard at Badger Graphics.

[Ernest Purdum]

Lensboards that are too thick are a frequent problem when mounting modern lenses. The difficulty is that the rear element will not seat properly, so the lens spacing is incorrect. Bad spacing = bad picture unless you are after soft focus effects. The remedy is to bore an oversize hole, then fit a patch on the front with the correct hole size. The patch can be metal or the very thin plywood available at your local model shop. This assumes that the lensboard itself fits properly. It sounds like this may not be true in your case.

[jason_3776]

i did actually get a recessed lens board from adorama. the only one they had was prety damn expensive though. more than $30-$40, & it was the only one they had for this. it is the typical thin metal plate I am used to seeing. it is also WAY to floppy in the thing. that 1/4" slot where it is supposed to fit lets it flop around all over the place. the unbored wood plate fits just fine, though. so maybe i should just use it, over bore for my shutter, properly bore a thin metal platte & then mount on that ? just seems like... work. i hate work. i guess i'll figure it out...

[Brian Ellis]

I don't know why the Adorama board flops around, Mitch's answer seemed correct to me based on the Tachihara I used to own and the boards I used with it. With respect to your recessed lens board question, the newer bellows that Tachihara uses are quite flexible and I think you could use a 75mm lens without a recessed board unless you are too restricted in movements. I tested a 65mm lens on a flat board and could focus it at infinity. I don't remember what the movements if any were like, I didn't buy the lens so I only made a few photographs with it for test purposes. But it did focus at inifinty and that was a 65mm lens on a flat board.

[Tim Curry]

Jason,

Is the slot where the lens board fits actually 1/4" deep? If so, you may have an older camera and will have to work with it as it is or modify it to accept newer boards. If it needs 1/4" boards, fear not, as there are ways around this.

You can use what is called a "rabbeting cutter" to mill out a shoulder in the back side of the board. Once the hole is bored for the proper shutter size diameter, this cutter can be used. Any decent cabinet shop will have one. Basically, it is a cutter which has a ball bearing (the pattern follower part on the bottom side of the cutter) which is smaller than the diameter of the cutter. It will cut a "step" in the back of the board to accept the rear lens element and the lock nut. Care must be taken to get the proper thickness for the nut and the proper diameter for the rear element.

An easier route may be just to add a "shim" piece of wood in the recess for the lens board. If you get the proper thickness, a normal lens board can be used then as it normally is. If you decide to do it this way, allow for a thin sheet of black felt to act as a gasket to let the lens board sit snugly against the opening.

No worries.

[Eric Rose]

I make my own lensboards. I just go to a hobby store and buy sheets of thin plywood they sell to model builders. Works great.

[Brendan Burke]

Yes, I just bought a "demo" Tachihara from Adorama and it has the same problem. I'm irritated with Adorama, since this camera clearly isn't of recent vintage. Not sure what to do yet...

[Brendan Burke]

Just got off the phone with Adorama. The camera I bought is NOT a Tachihara, but an Asian knock-off. Depite the fact that the description on the web said it was. They didn't seem particularly apologetic, and I'm not getting refunded for the return shipping. Live and learn, I guess.

[Ralph Barker]

First, Jason, is your Tachihara a 4x5 or an 8x10? They use different lens boards, and most of the answers so far appear to relate only to the 4x5.

Second, wooden lens boards vary in design. Some are thicker to ensure better dimensional stability (resistance to warpage), and may assume the use of a surface-mount flange. With modern lenses, as previously noted, it is often necessary to route a thinner area for the lens nut. Check the spacing dimensions of the lens-mounting hardware on the front standard, think about the light baffle at the edge of the lens board, and things should make themselves clear to you.