Need instructions for Aristo Cold Light/Zone VI Stabilizer

[Kimberly Prato]

I am a relative beginner and have acquired a Beseler 45M, Aristo D-2 Cold Light and Zone VI Stabilizer without any instructions for use, setup, etc. Can anyone help?

[David Lindquist]

I might be able to help you. First of all "is it all there?" The Aristo model D2 cold light takes an aluminum collar to fit it to the M series Beseler in place of the standard light housing, So if it's mounted already, you should be fine there. Probably good to mention that it is held in place by gravity so if it's one of the older M Beselers that you can rotate the head 90 degrees to project horizontally for really big prints, don't do that. The cold light head will fall off.

Your cold light head should have two power cords. One is the "heater". This is supposed to keep the head warm. The fluorescent tube (I'm going to call that the "tube") output is not so stable at lower temperatures. This is supposed to take care of that. The heater cord is plugged in to an outlet at least ten minutes before you want to start using the head. I'd unplug it when not using the enlarger as it will draw power as long as it is plugged in. The other power cord plugs in to the Zone VI stabilizer. This cord powers the tube itself. You can tell which power cord is which by plugging one of them in to a wall socket. If the tube lights up, it's not the heater cord, it's the one that powers the tube. If nothing much happens, it's the heater cord. In addition to make all this work together the cold light head needs to have a photo cell installed so the stabilizer can read and monitor the light output of the tube. I'm guessing that at one time this outfit was all together and working so the photo cell should be there. Is there a little receptacle on the top of the cold light? It probably has four holes. A lead from the stabilizer plugs in to this. It's probably keyed to go in just one way and has only 3 (not 4) pins.

If the stabilizer itself is like the one I'm familiar with, it's a black box about 5 X 7 X 3 inches. It has two cords coming out of it. One has a plug that plugs into the receptacle on top of the cold light head. On the box, this cord is marked "cell". The other is a power cord. On the box this is marked "Timer". It can is plugged in to a timer or an on-off switch (SEE WARNING BELOW). The box also has a three pronged outlet marked "Lamp". The cord from the cold light, the one that powers the tube, not the heater cord, plugs in here.

The front of the the box has a red and a green pilot light, labeled "Unstabilized" and "Stabilized" respectively. Also there are two knobs, one marked "Lamp Intensity" with a scale marked A-L with four additional unmarked divisions following the "L". The other knob is marked "Exposure Reduction (Drydown)" The scale on this knob is marked at 0%, 5%, 10% and 15%.

WARNING: I understand some timers are (were) not compatible with the stabilizer. I forget which suffered the damage if this was the case. I used an on-off switch and a metronome so this wasn't an issue for me. This may not be an issue with modern timers. Maybe someone else can elaborate on this.

Also don't use the stabilizer with an incandescent bulb. It will ruin the stabilizer.

So to sum up and to use the thing. The heater cord is plugged in about 10 minutes ahead of time to warm things up. The power cord (for the tube) from the cold light is plugged in to the outlet on the stabilizer box. The photocell lead from the box is plugged in to the cold light and the power cord from the box is plugged in to your timer or an on-off switch.

To use: After a ten minute warm-up, turn on the power to the tube. Turn both knobs all the way counter clockwise. Then slowly turn the "Intensity" knob clockwise. The light output of the coldlight will increase as you do this. The green "Stabilized" light should come on. At some point as you are rotating this knob, the green light will go out and the red light will come on. Slowly turn the intensity knob back counter clockwise until the red light goes out and the green light comes back on. Then turn the knob counterclockwise a bit bit more, maybe one division. At this setting or any lower setting the stabilizer is supposed to be able to keep the light output steady.

I think I'll stop here pending confirmation that the device I'm talking about is the same as the one you have. I think Zone VI had some later models of their stabilizer. If you have any questions, please don't hesitate to post them here or to e mail me. I can give a crack at explaining the "DRYDOWN" knob too, if you want.
David

[Kimberly Prato]

Hi David,

And thank you for replying.

The cold light was set up before, so I am assuming it includes the photo cell. There is a receptacle on the top, with three holes and there is a lead that fits it.

The stabilizer is exactly as you described and is plugged into a novatek 660 timer. The scales and knobs on the stabilizer match your description.

I don't understand the part about using the stabilizer with an "incandescent bulb". Does this mean only use it with the cold light?

Aside from that, I would appreciate an explaination of the "drydown" knob and anything else you are able to share. So far, everything you have said matches exactly what I have.

Many thanks for your help,

Kim

[Kimberly Prato]

One other question, I have read a little bit about the cold light on the web and so far I am unable to tell if this is the one for graded paper. Do you know how to tell if I am able to use this for variable contrast papers?

Also, I am assuming that the collar you described is attached. The Aristo is model D2-B (maybe for beseler)...???

thanks!

[David Lindquist]

Yes, the stabilizer is only for use with a cold light, and for 4 X 5 and smaller ones. An 8 X 10 cold light probably takes more power than the stabilizer can handle. And it cannot be used to stabilize the output of an incandescent bulb. Zone VI says “destruction of the unit is likely” if you try that.

Regarding the Drydown knob. Printing papers may show more or less of a tendency to “drydown”. That is a dry print will look a touch denser than it did when it was wet. The way this plays out, or at least seemed to for me, is you make your test strip and determine what looks like the proper exposure and then make the print. When it’s still wet it looks fine and once dry you look at it and think “Well that looks o.k. but I think it would have been a bit better with a bit less exposure. That is it’s not a really big difference but can be one that matters. To use the drydown knob to control for this Zone VI suggests the following sort of test. You do your test strip and make a properly exposed (i.e. to your eye and taste) print accordingly with the knob set at 0%. Then using the same exposure time make 4 additional prints, one with the knob set at 2%, one with the knob set at 4%, one at 6% and one at 8%. These four prints of course will look successively lighter. Develop, fix, tone (if you do that) and wash all the prints the same way. Leave the initial “good” print, the one done with the knob at 0%, in water, i.e. it stays wet. Dry the other four prints. Compare them with the wet “good” print. If, for example, the dried print that got the 4% decrease in exposure matches the “good” wet print, that is your dry down factor for that particular combination of paper/developer/etc. So then for that particular combination of paper/developer/etc. you can do your test strip/exposure determination with the knob set at 0%. Then when you make your print, set the knob at 4%. If all works as it should, this print, when wet, will look like it could use a touch more exposure and when dry will look like a “perfect” exposure. The photographic process being what it is, this isn’t going to be 100% perfect all the time, but it can help. Some papers exhibit more dry down than others. Maybe some show none at all. Others on this forum might help here. The literature with my controller, which is dated 1981, said at that most papers fall in the range of 3 to 8%.

I have a cold light head with the V54 tube, the one Aristo developed for use with variable contrast papers, and an older one with the W45 tube. I looked, the tubes themselves are not marked. The W45 glows with a white color, the V 54 has a definite green cast to it when you turn it on. Before the advent of the V 54 tube, Aristo recommended using the W45 tube with a CC 40 or 50 Y filter when using variable contrast paper. Over the years Aristo made other “colors” of tubes in addition to these two. My hunch is if you don’t have the V 54, you have the W 45.

I expect you do have the collar. I think if you didn’t, the cold light would fall through when you lowered the negative stage on the Beseler.

I can send you a copy of the instructions I have for the stabilizer. Mailing them would be simplest for me. E mail me your address if you want a copy.
David

[John Bowen]

For a good article on Drydown, check out Bruce Barlow's website http://www.circleofthesunproductions.com/documents/PartIII_000.pdf

[Kimberly Prato]

Hi John,

Thank you for the link....

Kim