Aristo VBL4500 Cold Light Head Dual Dimmer Model.

[Hedd-wyn]

Hi, I am looking for advice from someone who is using the Aristo VCL4500 Dual Dimmer Model of this cold light head. I am about to use this light for the very first time. The blue lamp is controlled by the dimmer knob on the main control box. The green lamp is controlled by the dimmer knob located on the smaller accessory control box. This smaller box has a scale that goes from 0 to100%. When the green lamp is set to 0 it seems to be just as bright as the blue lamp when the blue one is set to maximum intensity. When I move the green lamp's dimmer switch progressively higher toward 100%, it gets incredibly brighter and becomes almost white-green in colour. So this is the question: When I am split printing and using the blue lamp at it's maximum intensitry to get my shadow detail as per the instructions that came with the unit, when it says to use the green light at it's maximum intensity to get the highlight detail, does it really mean with the lamp maxed out at 100%? I just seems to be so bright.
I posed this question to Louise Kessler at Voltarc (who by the way are now producing the blue and green replacement lamps for this unit by special order for $260 per lamp) but she was unable to answer the question and directed me here.

My other question is directed at someone who has the standard model of the VCL4500 where only the blue lamp has a variable control. Is the green lamp on that model incredibly brighter than the blue lamp when the blue is maxed out? Just asking.

[Luis-F-S]

Unless the folks at LightTech/Aristo can shed some light (pun intended) I think you're going to have to resort to trial and error. I don't think these heads were sold in great numbers, and they may or may not be that reproducible from one to the next. Let us know how it works out. L

[ic-racer]

The paper is less sensitive to green. See what your printing times are like each way (green knob all the way up and all the way down). You will probably discover the benefit of the green light being about twice the brightness of the blue light. (The colored lines on the graph represent exposure needed to produce a constant gray value. The lines are colored just for the sake of clarity, the colors don't mean anything)

[Gudmundur Ingolfsson]

I have the instructions for the 8x10" unit. It's 4 pages if it will help I can make a PDF tomorrow and mail to you or post it here.

[jeroldharter]

It has been awhile but there are also some toggle switches that you need to fiddle with. It sounds like you need to flip one.

[Hedd-wyn]

Hi,Thanks everyone. The green light evidently is way brighter than the blue in both standard and dual models. The green is also used maxed out for the split printing. The dimmer is to reduce short printing times if necessary to allow for dodging and burning. Hedd-wyn