robert_johnson11 Posted May 12, 2003 Share Posted May 12, 2003 Greetings all, I shoot 5x7, 8x10 and 12x20 landscape and industrial photos, and just completed (after a year of headaches and heartaches and 40 years of using substitutes) a new darkroom, with enough room for once! In it I have just set up a condenser-head 10x10 Saltzman enlarger and am preparing to give it a trial run. It was rebuilt (by our shop; we do LF camera restorations, etc.) and is a truly beautifully built piece of machinery, if one only has enough ceiling height and strong enough floors! Recently while cleaning out a commercial darkroom from a local company that was going out of business, I acquired a small device called an Lum-O-Tron. It is model Tron-L, serial number 1162, built by the Alignotron Corp. I can find nothing on the Internet about it; presumably the company is out of business? The owner of the shop said that it was used to align their enlargers, but he never used it and couldn't find any instruction manuals for it. He had, in fact, thrown it into the wastebasket, where I spotted it! (He also had thrown out 100, 500-sheet boxes of Kodak paper; that's another story too depressing to relate!) It measures 2-1/4 inches wide x 8 inches long, has a meter reading 0-20 on both sides of a center zero, plus a knob reading 0-70 which turns it on. It is battery powered. At the far end there is a small laser that apparently projects its beam through a marked target on the top up into the enlarger. I replaced the battery and this laser lights when turned on. Does anyone know how to use this device, and/or where to obtain instructions? Many thanks, Robert Link to comment Share on other sites More sharing options...
nathan_congdon Posted May 12, 2003 Share Posted May 12, 2003 In principle, you'll want to place the "Alignotron" on the easel/baseboard, mount a mirror on your enlarger's lensboard, fire the "Alignotron" laser at the mirror, and adjust the baseboard and/or lensboard until the reflection of the laser dot comes back dead center on the machine. Then repeat the procedure mounting a mirror on the negative carrier (but this time adjust the negative carrier only). When you have the beam perfectly centered when reflected back from both the lensboard and the negative carrier, all three critical planes of your enlarger are perfectly parallel, which is of course ideal. There are a number of commercial devices out there to do the same thing. Things to watch for: 1. Not all mirrors are perfectly flat. The device I bought came with its own glass. You might want to see about buying or borrowing an appropriate mirror or piece of glass (Check out this URL for pointers to other commercially available devices, where you could likely get the glass you need: http://www.zig-align.com/lasers.html Obviously, small flaws in the optical surface will mess up your measurements.) 2. The device I had came with a rubber band (!) to mount the glass in place. Depending on how your enlarger is constructed, you might just be able to place the glass on the lensbooard, neg carrier, or you might have to use a rubber band. Just be sure the glass is perfectly flush. Good luck with your new baby! Nathan Link to comment Share on other sites More sharing options...
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