I believe the flicker that Mr. Adams referred to was the start up flicker when the enlarger is turned on. The older bulb/ballast combination could/would/did ignite and quit several times before they would stabilize, effectivly reducing your $300 digital timer accurate to 1 millisecond to being a paperweight. The paper probably does not realize it is getting 120 light pulses per second - the idea of using DC is interesting, though. That may help stabilize the lumen output of the lamp as it would warm up quicker. If you are using a variable contrast paper, think about the color spectrum of the lamp you select - you may find that printing grade 5 to be impossible > --__--__-- > > Message: 2 > Date: Wed, 13 Jun 2001 13:19:29 -0700 (PDT) > From: Matt Mengel <[EMAIL PROTECTED]> > Subject: [Cameramakers] Speed Graphic Enlarger > To: [EMAIL PROTECTED] > Reply-To: [EMAIL PROTECTED] > > Ron, > I know someone who does neon (I think). Are the green > and blue to work with variable contrast papers? Why > couldn't I use a standard enlarger bulb (or bulbs) and > space them evenly over some diffused glass? Not even > enough distibution? > Stabbing in the dark, > Matt > > > --- Ron Baker <[EMAIL PROTECTED]> wrote: > > Hi Matt > > I believe that most modern cold lights use a form of > > neon tubes in lew of > > florescent tubes. I have owned both a regular cold > > light from Zone VI and > > there variable contrast head with the blue and green > > tubes. I have thought > > many times about stopping at the neon sign > > manufacturing business here in > > the town I live in but haven't gotten around to it. > > Ron > > www.ronbakerphotography.com > > > > ----- Original Message ----- > > From: "Matt Mengel" <[EMAIL PROTECTED]> > > To: "Cameramakers" <[EMAIL PROTECTED]> > > Sent: Wednesday, June 13, 2001 7:20 AM > > Subject: [Cameramakers] Speed Graphic Enlarger > > > > > > > Thanks everyone on the suggestions for the Graflok > > > back. In Ansel Adams' book "The Negative" he has > > > drawings of a homemade diffuser enlarger using > > anti > > > flicker "special" flourescent tubes as a light > > source. > > > Anyone have any info on something like this? The > > book > > > has a good diagram but not much detail on > > > construction. > > > I'd like to make the stuff myself as opposed to > > buying > > > a cold light. But it's good to have the Graflok > > thing > > > to fall back on. Would a good light box be a good > > > starting point? For parts that is. > > > Cheers, > > > Matt > > > > > --__--__-- > > Message: 4 > From: "Ron Baker" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Subject: Re: [Cameramakers] Speed Graphic Enlarger > Date: Wed, 13 Jun 2001 16:51:11 -0500 > Reply-To: [EMAIL PROTECTED] > > Hi Matt > Probably any light source will work but you have to keep in mind the heat > factor. You will want to keep everything as cooool as possible. > Ron > I prefer using a dicro head with the yellow and magenta filters this will > allow me to do color if I choose to. You can pick up an old Beseler DG color > head very reasonable ,$100 -$200.. I like the DG head because the cooling > fan is separate from the light head it's self. > > > > ----- Original Message ----- > > > From: "Matt Mengel" <[EMAIL PROTECTED]> > > > To: "Cameramakers" <[EMAIL PROTECTED]> > > > Sent: Wednesday, June 13, 2001 7:20 AM > > > Subject: [Cameramakers] Speed Graphic Enlarger > > > > > > > > > > Thanks everyone on the suggestions for the Graflok > > > > back. In Ansel Adams' book "The Negative" he has > > > > drawings of a homemade diffuser enlarger using > > > anti > > > > flicker "special" flourescent tubes as a light > > > source. > > > > Anyone have any info on something like this? The > > > book > > > > has a good diagram but not much detail on > > > > construction. > > > > I'd like to make the stuff myself as opposed to > > > buying > > > > a cold light. But it's good to have the Graflok > > > thing > > > > to fall back on. Would a good light box be a good > > > > starting point? For parts that is. > > > > Cheers, > > > > Matt > > > > --__--__-- > > Message: 6 > From: "ken watson" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Date: Wed, 13 Jun 2001 15:34:48 -0600 > Subject: [Cameramakers] RE: Cameramakers digest, Vol 1 #132 > Reply-To: [EMAIL PROTECTED] > > Thanks everyone on the suggestions for the Graflok > back. ... anti > flicker "special" flourescent tubes > > I do not know for certain but I would bet if you had a dual power supply to > the lamps you could stop the flicker. Flickering is caused as the current > changes direction inside the tubes. You need AC power to strike the arc but > once it is going DC would do the trick. > As a suggestion get 300V caps and feed them rectified AC ( pulsating DC ) > from the power line with a diode ( 1 KV rating might be required) in series > with the output of these caps connect them in parallel to the same AC > connections to your lamps. By having a switch for the AC side and DC side, > once the bulbs were lit off you could switch off the AC power stopping most > or all the flickering. Caps for this might be cheapest from someone who > supplies them for motor starting. Using 'AC" caps vs DC would be an OK > substitution and keep things from getting exciting if the DC caps were > installed backwards. Keep everything "unplugged" until you are finished > wiring everything. > Of course if you REALLY wired things wrong there are circuit breakers. Also, > for real, this could lead to a dangerous situation where, if things were > wired incorrectly, you could place the "wrong " side of the AC line to the > fixtures. So make sure they ( the fixtures) are grounded and find a GFI plug > for your first test. > If you have no idea of what I am talking about do nothing. Or find an > electrical or electronic engineer friend to figure things out . > > --__--__-- > > Message: 7 > From: [EMAIL PROTECTED] > Date: Wed, 13 Jun 2001 19:16:25 EDT > Subject: Re: [Cameramakers] Speed Graphic Enlarger > To: [EMAIL PROTECTED] > Reply-To: [EMAIL PROTECTED] > > --part1_d3.162c141e.28594e49_boundary > Content-Type: text/plain; charset="US-ASCII" > Content-Transfer-Encoding: 7bit > > Hi Matt, > I think your on the right track with the multiple lights and the diffusing > material. I tried a piece of lexan under the condensors of my D5 and it did > work giving a nice diffuse light source,but the light output was reduced > dramatically and made the exposures longer than necessary. I tried a higher > wattage lamp but then this smell of burning appeared so I gave that up. I > have thought about using one of those 200 watt long life fluorescent bulbs. > I also had another idea thanks to a neighbour who installed one of those > outdoor mercury vapour lamps it kinda looks like an enlarger lamp housing and > by the light it puts out bright enough,maybe you could check one of these out > at a d.i.y place. My final idea( but not sure of the power aspects of it) > would be to use the halogen lamps from car headlights ,maybe you could obtain > a couple of volvo headlights and place some opal glass in front or make a > mixing box and bounce the light onto the diffusing bit. you would need a > power supply for the 12v but the lamps are cheap. Also along this idea what > about those searchlights used for hunting they maybe bright enough. > hope this helps some and let us know how your experiments go > Regards > Andy > _______________________________________________ Cameramakers mailing list [EMAIL PROTECTED] http://rmp.opusis.com/mailman/listinfo/cameramakers
