Beseler Color Head questions

[ryanmills]

I just got a used Beseler 45s. Have a few basic questions.

Important one I cant zero all three colors, is this normal? Im printing on b/w vc paper and yellow wont go below 25 so i can really get a grade 2 setting. Wondering if I need to replace the lamp. Second there is about a .8 second delay from when the timer starts to the lamp firing up, is that normal? My timer goes down to a 1/10th of a second so its easy to compensate, just wondering if its normal. Lastly i cant add magenta without the yellow going up, again wondering if the lamp needs to be replaced or if thats normal?

[jp]

The color head on my Beseler cb7 needs some lubrication when I got it to make the color dials work right. Basically lots of little pulleys like in an old car radio to operate things from the knobs. I'd suggest cleaning the innards and lightly lubricating any moving parts associated with the dials or moving mirrors. All dials should work independently of one another.

[Kirk Gittings]

Is that the head with the digital readout? I printed color with one of these for years. The filters age and change colors slightly. You need to zero it out by dialing in some of the other two colors. There is no "zero" color but a neutral color balance which can be achieved by adjusting all three.

[ic-racer]

Which color head do you have (post a picture if not sure.)

[Jon Shiu]

Maybe it would help to say how a dichroic head works: the 3 filters partially block the light source and the amount they are blocking determines the number, ie totally out of the pathway is 0, totally covering the pathway is max, like 170CC. They are usually controlled mechanically with cams, levers, springs and can get stuck or out of whack. They should go to 0 and are independently controlled. Also, the white light control would move them totally out the way.

Jon

[ryanmills]

108747

This is mine.

I tried to zero yellow by using the screw on the bottom but it was already as low as it could go. I swapped lamps but it made no difference, i checked and the plates move freely of each other and dont seem to stick, it was dusty so I cleaned it out. Still the lowest I can get it is Y:22 M:0 C:0 now I am doing this in density mode, if I change to filter i can use cyan to zero yellow by cranking cyan but I read that was wrong. Any other ideas or can i simply subtract 22 from whatever number yellow is?

[Jon Shiu]

Okay, forget what I said, that is not a Dichro 45S model, which is a more simple head.

Jon

[ryanmills]

Okay, forget what I said, that is not a Dichro 45S model, which is a more simple head.

Jon

Oops I thought it was, my mistake.

[jp]

That's different than mine (which has analog readouts). Open it up and see how it works.

[George Richards]

108747

This is mine.

I tried to zero yellow by using the screw on the bottom but it was already as low as it could go. I swapped lamps but it made no difference, i checked and the plates move freely of each other and dont seem to stick, it was dusty so I cleaned it out. Still the lowest I can get it is Y:22 M:0 C:0 now I am doing this in density mode, if I change to filter i can use cyan to zero yellow by cranking cyan but I read that was wrong. Any other ideas or can i simply subtract 22 from whatever number yellow is?

That would be the "infamous" Dichro 45C (Computerized). Infamous for the poor quality of the PC board connectors - mine came with a chunk of cardboard to hold the boards in place. I only used it for a short time - had to reset the boards once. Replaced it with a 45S then replaced that with an Ilford 500 system. While I had it set up I too had trouble zeroing the yellow. I think I got it close but not all the way to 0. I suspected a couple things. The system tries to measure the actual light rather than then the filter setting. 1) the lamps could be old and too yellow 2) the diffusion chamber has yellowed with age 3) the sensors use filters that may have changed over time. Those were my guesses but as I say it's collecting dust on the shelf.

best of luck

George