Saturday, May 22, 2010

More experiments with the Zone VI.

The print in the upper right and lower left are the same print with a contrast setting on the variable contrast controller of CD or one level higher on the "hard" contrast (D) control then the "soft" contrast (C) control. I determined exposure after doing a test print in 2.5 exposure unit intervals.   I chose the exposure I liked the best and ran a series of test sheets  keeping the same exposure unit setting but changing the differences between the settings of "hard" and "soft"on the variable contrast control unit.  What have I learned so far?  Always make sure the unit is warmed up with the pre-heater switch turned on and perhaps turning the lights on for a couple of minutes to warm them up before running test prints.  After making this series of tests and feeling like I had accomplished quite a lot I realized I had left the pre-heater off which probably screwed up the exposures for each test print.  Another thing is I have to stop thinking of contrast using this dual light, variable control system the way I think of gel filters with a constant light source.  Each dial controls one tube.  The "soft" control is attached to the green light.  The controls from minimum to maximum with levels A-H between the extremes
control the light output like a dimmer switch.  The controls are the same for the "hard" or blue light.  To have the "soft" light on and the "hard" light off would be close to making a print with a 0 filter and a single balanced light source like a cold light or a incadescent light bulb in a condenser enlarger.  To have the soft light off and the hard light on would be the equivalent of a 5 filter more or less.  The differences between the two yield the different wave lengths of light to impact the different contrast emulsions in variable contrast paper.  If I start off by making my test exposure of a particular negative one way to do this would be to set the controls at equal levels probably each one in the middle of it's control say each at "D" then to increase contrast I would first change the difference between the soft and hard controls say D/E, D/F, D/G,D/H, D/Max.  If I still wanted higher contrast I would then begin to lower the soft settings C/Max, B/Max,A/Max,Min/Max, Off/ Max using the hard light exclusively.  If I wanted to soften contrast I would do the opposite reduce the hard control keeping the soft control at D and decreasing the hard contrast control;  D/C,D/B,D/A,D/Minimum, and if I still wanted to cut contrast begin increasing the soft control; E/Minimum,F/Minimum,G/Minimum,H/Minimum, Max/Minimum,Max/Off. AA and HH would be the same contrast setting but a less intense light for AA if you had a negative of low density (under exposed) HH if you had a negative of high density (over exposed). This  ability to vary the light intensity is new to me in printing and this is where the compensating timer made for this system becomes essential.  If I have the hard and soft controls equal and do a test strip to determine the proper number of exposure units I can maintain the same number of exposure units but by changing the controls to either decrease or increase the volume of light will be compensated for by the timer.  Equal light at a particular level may come out to each exposure unit equaling one second.  Lowering the light by half would change the exposure unit to two seconds, Doubling the light would change the exposure unit to 1 half-second.


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