This isn't the answer you are looking for but. . . Losing light is easy. Often when I have two lights set up for copy work and I want to vary one of them--to get a single instead double shadow on a painting with a thick paint gloops I clip a Neutral Density gel in front of one source. .3 is one stop .6 two (I think that's the way it goes.) There are subltler ND steps.
Another easy method is based on the Inverse Square Law. When you move the typcial light source 140 percent of its distance the light drops a stop. (1.4 squared is 2) Conversely 70 percent will get you plus one stop. focusing fresnels, reflectors and soft boxes affect this but for the most part it work. So if your light is about 3 feet away move it to 4.5 or to 2 feet or anywhere in between. Course I never properly learned to to dial up and down my power packs. The reason being 'back in my day' the modeling lights were not proportional to the flash output. We'd usually put everything about the same and then move the stands around. I still don't fully trust 'em. Another duh-thing we'd do, especially when we needed to speed up the duration for a liquid pour shot is to put another head or two on the pack and point the un-needed light out the window. This also cuts down the light, but I shutter in shame when I think of all the wasted photons. I read once that the Norman power packs were the first and that they were initially made during WWII. They would fit in a B-17 or B-24 bomb bay. Reconnaissance would fly over a recently bombed German target at night and they'd shoot flash bomb damage assesment photos. On the east coast in the 1970s it was consider state-of-the-art to use Speed-o-Tron heads with modified cords and Norman packs. If you still want to play with solder and rheostats I'd contact a good flash repair place. Will ---William Nettles [EMAIL PROTECTED] Nettles Photo / Imaging Site http://www.wgn.net/~nettles Find out what's happening in Echo Park: [EMAIL PROTECTED] > From: [EMAIL PROTECTED] > Reply-To: [EMAIL PROTECTED] > Date: Tue, 9 Apr 2002 12:07:07 -0600 > To: [EMAIL PROTECTED] > Subject: Cameramakers digest, Vol 1 #380 - 1 msg > > A little off the beaten path of camera building, but I know many of you are > do-it-yourselfers on other issues. I am looking for some assistance on > modifiying a Speedotron Brownline system to get a greater range of power > adjustment. When using a digital camera to proof setups I need less light > than when shooting the final shot with my 4x5. The Brownline offers 2 stops > adjustment but I would like to get 3 or 4 if possible. Does anyone have a > source for schematics on these power supplies? My second option would be to > modify the heads with a 1 or 2 stop adjustment similar to what Novatron does > on their heads. I have left a message with Speedotron but not gotten a reply > to my request for a schematic. > > Before the replys about the danger of working on strobes start let me say, > yes I know. I am aware of the danger but know how to deal with this type of > "low voltage" equipment, I spent the first 20 years out of school working on > 7500 volt equipment. > _______________________________________________ Cameramakers mailing list [EMAIL PROTECTED] http://rmp.opusis.com/mailman/listinfo/cameramakers
