I put this out on another post, didn't get any reaction, but I still think it has value.
I use the same enlarger and split print because my green and blue lamps are either on full or off, no proportional values.
I printed out a step wedge to get these percentage green and blue times for different grades.
The spacing in my post doesn't come through, but just follow the headings in order in each line
Grade Blue Green Stouffer steps (21)
5 100% 0% 5.5 steps
4.5 80% 20%
4 76% 24% 6 steps
3.5 52% 48%
3 43% 57% 8 steps
2.5 35% 65%
2 28% 72% 9 steps
1.5 22% 78%
1 18% 82% 10 steps
0.5 12% 88%
0 8% 92% 11.5 steps
00.5 3% 97%
00 0% 100% 13.5 steps
Robert, I will assume that the bulbs in your enlarger do follow the rheostat, I.e. they are not limited to completely on or off. The following is a good starting point for settings and exposures: www.bnimages.com/files/zonevicontrast.pdf
It will need some personal modification since the contrast of your negatives plays a role (at least it does for me).
CowanW: This is the percentage splits of two separate exposure that together would make up 100% of the exposure time, correct? So two exposures for each print? Interesting method, if I am understanding it correctly. Does your enlarger not change color as you move the rheostat? So you just print at one end of the scale or the other?
Yes, the rheostat gives me only on or off, although the dimmer works as does the focus/timer switch. But no, not at one end or the other, but at one end of the scale and the other,as there is an infinite combination of the two exposures
So it functions as a split printer, which I think simplifies things, one brings the blacks up and the other brings the whites down.
While the actual grade of the print is some what academic, the chart helps me move between my other two enlargers both yellow/magenta, grade for grade.
Incidently 10 sec on green plus 10 sec on blue does not equal 10 sec on green and blue.
Robert, one other hint that I'm not sure is written up: The head has a stabilizer circuit that works with the heater to keep the exposure "lumens" constant (otherwise the intensity can drift a bit, making successive prints not as predictable as they should be). There is a little green diode on the head which glows when things are stabilized, and goes off when they are not. In my experience, if you are not making an exposure for a few minutes, so the bulbs cool down, the head can become "unstable." So I make it a habit to put the enlarger on "focus" when my print is in the fixer, which warms everything up again for my next exposure. Otherwise what sometimes happens to me is that on, say a 30 second exposure, the green light will either not be on when I start, or perhaps go out during the exposure. I don't know if this is true for all of the zonevi heads, or if my heater circuit is not working as we'll as it should. Just keep an eye on that diode when you are printing.
I've heard that the three-knob controller for the Type II enlargers can be optimally adjusted to the particular head. You could check this out by calling the Calumet repair shop.
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