Zone VI condenser cold head enlarger question

[Nikanon]

I have a Zone VI condenser enlarger that has a special dial system attached to the main on and off configuration that controls variable contrast. On this there are three dials, one for soft, one for hard, and one for brightness. I am not sure whether to mix hard and soft to get maximum contrast, or simply just use hard for higher contrast, and soft for low contrast, and if mixing the two even does anything but lower my effective paper sensitivity? Does the brightness dial change the degree to which the filter dials are effective, or is it just a simpler way to adjust the print density from an easy dial instead of changing the time? A quick verbal demo on how this thing works would be awesome! (im already assuming the hard dial controls the magenta filter , and the soft controls the yellow, but I may be wrong here too!)

-JH

 

[cowanw]

Not magenta and Yellow, but blue and green. Yes the hard and soft are what you think, as is the light intensity knob.
I expect most just use high on the brightness. I use the blue and green separately, as I found the combination settings to difficult without extensive testing to predict the grade achieved. In theory one could figure out settings for each grade with constant time. Be nice if Ilford included zone vi with it's contrast settings chart.

 

[ic-racer]

Brightening the green light will darken highlights and brightening the blue light will darken shadows. Both will affect the mid tones.
I think most people use that additive system in a 'freestyle' manner, tweaking the knobs to get the desired effect in the print.

It is possible to calibrate this so it works like the constant-exposure multigrade filter sets. This link shows one way to do it. http://www.jbhphoto.com/articles/vccl/vcclcaljbharlin1.pdf

 

[TimVermont]

Hi JH,

Some of these heads are brighter than others, and the individual tubes can vary-mine is very bright on both tubes. They can be very confusing to work with, and consistency is important, especially if you aren't working with consistent negatives. You will want to setup a grid or spreadsheet to record your settings for your prints. Start with a negative that you've printed well previously. Turn the brightness dial to about 3/4's full. Turn the hard dial to off. Turn the soft dial to the middle of its range. Pick a dark area in the negative that you want to be a delicate highlight. Make a test strip of this area and pick the best rendering. Use a step tablet if needed to refine your pick-it is easy to over/undershoot, and you must process and dry the test strip before evaluating it. If you find yourself using a tiny f-stop and a short exposure, reduce the brightness and try again. Write down the f-stop and exposure time and the dial settings. Now turn the soft dial off, and turn the hard dial to the middle of its range. Make a test strip on the unexposed rebate (margin) at the edge of your film and pick the first well rendered almost full black ("almost" to account for the soft light exposure). Combine these two exposures to give you the base exposure for a print.

The ability to use the lamps separately for dodging and burning is a great help in refining the print.

All of this can be automated with a Heiland Splitgrade unit and controller if you need to print quickly.