At 03:19 PM 9/21/2002 -0400, you wrote: >Thanks Bob - I think in my case a little knowledge is dangerous - I worry >more about what I do NOT know than what I do...with the hope that eventually >when I know it, I'll be the first to know. > >And AZ (panoramic), I would like info (off list or on, whatever's >appropriate) on custom lamp...I had thought about a neon place locally that >makes weird custom neons. > >Are you talking about something similar to the 'grid lamps' Arista/o makes? > >Murray > > > ********************************* Enlarger lamp instructions.
I have had several lamps made for my panoramic enlargers at neon shops. I had a green/blue set made for variable contrast. It was a pain in the butt to use without a fancy computer timer so I didn't use it except for extreme contrast situations where I only needed green or blue. I have a picture of a lamp for a 2 x 7-1/2 inch format here: http://www.panoramacamera.us/enl_lamp1.jpg Use 9mm dia. tubing with cold white phosphor. Make a full size pattern of the lamp. Explain to the glass maker that they have to bend the tubing in a flat zig zag that covers whatever format you need. The bends and cathode/anode should be on the outside of the format size. The distance between each length of tube is the same as the diameter. The cathode/anode should bend upwards slightly from the face (or even more to save space). Beg for a used sign transformer that will give you enough zap. They know what sizes. I have a 9000V, 30ma transformer on a lamp with four linear feet of glass which is pretty hot. Use black foam-core (best) or 1/4 in. ply. for the housing and mount the grounded transformer on the wall out of the way. Don't have it where it can be accidently touched. Regular zip cord appliance wire is OK for connections but keep it away from metal and you! Wood or foam-core is an OK insulator but not UL approved. Get a set of bananna plugs at Radio Shack for the connections. To protect the lamp mount it on a piece of 1/16 clear plex with light wire thru pairs of holes in the plex or use clear tape or dabs of silicone calk. I used 1/8 in. milk (skim!) white plex for a diffuser with the glass about a half inch away. The sign co. may have this. An alternative is clear plex with layers of frosted mylar or tracing paper. Use white cardboard on top and sides of the lamp for a reflector. When the lamp is on the individual runs should not show. It may take some testing and adjusting. Even Aristo and Ilford lamps can need some adjustment for uneven lighting. The shutter assembly is easier to make than explain. It's design is from an ancient Omega 8 x 10 enlarger with old style fluorescent lamps that remained on at all times (modern enlarger lamps use a pre-heated cathode system). It can be made any number of ways. Any small motor (like from a hair dryer) will do. The shutter is mounted below the lens. How this is done will of course depend on your enlarger. Mount a pivoting shutter (paddle shaped mat board) to the motor armature axle. I used a motor with a small cooling fan and cut away all but one blade of the fan and tape the shutter to the remaining blade. Use a thin rubber band and a bumper stop to cause the baffle to return closed when the power is shut off. It takes a bit of trial-and-error but once you see it working it is obvious what to do. Fasten a piece of soft foam material to the bumper to absorb the momentum of the returning shutter. The motor is connected to the enlarger lamp outlet of the darkroom timer (remember this is a switch - half the circuit - and can switch low voltage DC motors too). The lens shutter should swiftly rotate completely open (about 100 degrees) when you punch the timer, and close completely without bouncing. It is a contraption and may require a bit of tape and bubblegum to work the way you like it. Once it is adjusted it will be trouble free. AZ Maker of Lookaround panoramic camera. http://www.panoramacamera.us or keyword.com lookaround _______________________________________________ Cameramakers mailing list [EMAIL PROTECTED] http://rmp.opusis.com/mailman/listinfo/cameramakers
