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Hedd-wyn
6-Dec-2015, 16:39
Hi, Just getting into 4X5 processing. Determined personal film speed using Fred Picker's Zone VI testing method. (my speed: 250 for TMX 320 processed in a Unicolor print drum and motorized base for 7 min. giving me a Zone 1 of .11 above fb+fog)

To calibrate my Aristo VBL 4500 cold light head, I used Steve Anchell's method, utilizing a projected 31 step wedge as outlined in his book "The Variable Contrast Printing Manual". With 2.0 set on the cold light controller, I get an 11 step wedge that corresponds to an ISO Range # of 105 which in turn corresponds to a paper contrast grade of 2 on my Oriental Seagull VC-FB II glossy paper when the step wedge is exposed at f8 for 10 seconds.

So far so good, as my reading has led me to understand that my initial goal is to produce a properly exposed negative that will print on a #2 grade paper, hence all the effort testing my VC paper to get a #2 contrast grade.

The final step is to find a personal film development time that will render a Zone VIII placement as a Zone VIII print value.

To do this I went back to Fred Picker's Zone VI method and this is where I became somewhat confused. In his instructions he initially wants to find the minimum printing exposure time, using an unexposed but fully processed negative, that will produce a maximum black. He then uses this time to determine which of your Zone VIII negatives have been developed for the correct time. Again,I didn't have a problem understanding this.

Where the problem came in was his instruction to use either your normal grade 2 paper for the test or (and this is where I became confused) or a piece of variable contrast paper BUT NO FILTER

Am I missing something here? Why wouldn't I be trying to get my Zone VIII negative to print on my #2 cold light setting for the VC paper? After all, isn't that what I am striving for, a negative that will print on a grade 2 paper? Once I dial in the green and blue light filtration to produce a #2 contrast, the amount of light reduction that would take place would surely require a different density of negative to produce a Zone VIII
on the paper than one to produce a Zone VIII on an unfiltered piece of VC paper.

I'd really appreciate someone sorting out my reasoning, which right now, appears to be faulty. Thanks

Peter Gomena
6-Dec-2015, 17:33
Supposedly, using no filter is equivalent to using a #2 filter. In your case, you want to use your personally established #2 setting. You have no filter, but you have calibrated your enlarger to where you want it.

Bill Burk
6-Dec-2015, 17:49
I'd say build on your work to find "Grade 2" and use that.

David Lobato
6-Dec-2015, 17:53
Picker probably assumed the reader would be using replaceable filters in the light path, such as Ilford Multigrade filters. With that system no filter equals a #2 setting.

Hedd-wyn
7-Dec-2015, 00:23
Hi, Thanks for the quick replies. Hadn't realized that non filtered VC paper had a grade 2 contrast. Makes sense for non filtered light sources though. Much appreciated. Glad to know my work wasn't wasted. I've just nailed down my Zone VIII development time so on to the proper proof!