Remounting a lens

<p>I'm considering purchasing a field camera that comes with a Linhof Technika style lensboard for a 0 shutter. I have lens lens on my Calumet 45N, a 150 mm f/5.6 Sironar. It is in a 0 shutter. My question is, how tricky is it to remove such a lens from one lens board and mount it on another? I don`t imagine that I'd be able to use one board on both cameras.<br>

Any thoughts?</p>

<p>Not tricky at all. you unsrew the front and the back element and the back of the lensboard you will find an retaining ring which is on the back of the shutter. Unsrew it and than the shutter is free to mount on the new lensboard. sometimes you will find a little stift on the back of the shutter check if it fits in the new lensboard otherwise you got to udjust a little. It's because that one holds the shutter in the right position and its not gonna turn aound while you working.</p>

<p>The easiest way is to buy a Linhof adapter board for your Calumet camera. That will let you use the Technika board on either camera.</p>

<p>As Bob wrote, you can mount the lens on the smaller board and buy an adapter board for the camera that takes the larger board. Since the lens is already mounted in the larger board, you will want to move it to the smaller Technika board. This is easy to do. It helps to have a spanner wrench so that you can properly tighten the retaining ring. The flat sheet metal ones made by Linhof and Toyo work well for standard size shutters on flat metal boards.</p>

<p>Here are some past threads on mounting lenses to lensboards: "Mounting lens on lensboard - could a beginner do that?" at <a rel="nofollow" href="http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=003k3c">http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=003k3c</a> , "Help mounting new lens on board" at <a rel="nofollow" href="http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=0090M8">http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=0090M8</a> and "Help with mounting a lens" at <a rel="nofollow" href="http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00Ev3Q">http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00Ev3Q</a> .</p>

<p>Richard, I would strongly endorse Bob's recomendation. I have the same view camera that you have (Cambo) and with it's 6 3/8" boards it very easy to adapt to smaller boards like the Technica's and it works very well; my second camera is a Super Graphic who's boards are just over 3" and I have most of my lenses mounted on the little aluminum boards for the Super and made my own adapter board for the Cambo since I didn't find one when I looked. Very easy to make with those big boards and it works great! the only lenses I still have on Cambo boards are some short lenses that needed recessed boards and some very big heavy lenses that just need big boards. You will find that it is very convenient to have your lenses set up so that they can easily be used on both cameras!</p>

<p>Humm? There might be one fly in the ointment. A long time ago I unscrewed my lens to send the shutter away for a clean and lube. I found a shim in the configuration and (may have been posted on here thinkin about it) it seems this was to set the lens up for best resolution.</p>

<p>Now I don't know why the shim was required...odd sized board? previous owner realy really wanting to fiddle with things to get things perfect? I dunno but there must have been a reason for this being there.</p>

<p>The shim was probably to correctly set the spacing between the front and rear lens groups. If you still have it and remember where it was (between front group & shutter or between rear group & shutter, put it back in the same place. If you don't still have it and are getting sharp pics, then don't worry about it.</p>

<p>When I have seen lenses with shims, they have been between the front lens cell and the shutter. This makes sense -- the owner is less likely to unscrew the front lens cell and damage or lose the shim. Unless the rear lens cell has an unusually small diameter, is necessary to unscrew the rear lens cell in order to mount the lens to a lens board. Shims are common on super-wider coverage lenses such as the Nikkor-SW and relatively recent designs (Super-Symmar HM?, Apo-Symmar-S?). Some lenses have shims to change their optimal reproduction ratio, near subjects versus distant. Perhaps some owner may not know that the small screw behind a Copal shutter is removable and use a shim to space the shutter away from the board?</p>

<p>But the question is how would Richard Todd know if he needed a shim in his new lens environment?</p>

<p>He could use a micrometer to measure the board thickness & shutter thickness and hope that the old setup and new setup are equal. But even if they did match how would he know if a shim was initially required? He may think he's getting sharp pics but in isolation that's a difficult call as someone may come along with the same lens and be getting even sharper pics.</p>

<p>Years ago people would send their lenses off to a place called S K Grimes in the USA for this type of thing. Ah I've googled them and see they are still in business for lens mounting:<br>

<a href="http://www.skgrimes.com">http://www.skgrimes.com</a></p>

<p>Or maybe I'm just too blummin' pessimistic! :-\</p>

<p>Normally the lens board goes behind the shutter and doesn't change anything about the spacing of the optics. So ordinary mounting of a lens doesn't require an shim for optical spacing -- the OP shouldn't need to be concerned about this issue. In rare circumstances you might need to space a shutter in front of of the lensboard, perhaps to allow a very large shutter to clear some obstruction -- this would be a mechanical shim that wouldn't need optical tests.</p>

<p>Thank you all for your many suggestions and observations. I think that even under the most optimistic scenario I'd be unwise to attempt the remounting myself, though Michael Briggs offers a ray of hope. I believe that I'll hold off on getting a field camera anyway. I was going to pay for it with the proceeds of a show I had last weekend. The proceeds were not up to the task, so I'll go toting the monorail, I suppose. Not ideal for hiking in the hills, I'm afraid.<br>

Thanks again.</p>