VC versus color head for BW printing

[Dick Laferera]

Any opinions out there concerning the advantages of using a color head for printing black and white vc paper over a vc head, or vice versa?

[ronald moravec]

Color heads will produce the same result with more work. How much extra depends upon the head. My Leica V35 color module is easy to set and does not have all the neutral density of the VC module. My Chromega 4x5 is a pig to set for VC because of the small dim numbers. I usually use my D2 condenser with Ilford filters mounted on cardboard frames that fit the filter drawer.
Ya it`s 1949 technology, but I like it and the prints are just as nice as from my V54 Aristo or Chromega, maybe nicer.

35mm black and white printing is not done with the V35. I use a focomat IC. The filters are fastened to wooden fixtures that precisely fit where the metal filter drawer is supposed to go. I made about 12 of them, one for each filter and one with nothing which is what is usually in the machine.

I guess that tells you what I think of diffusion printing. I own all the latest stuff and still use the oldest technique there is .

To more precisely answer your question, VC modules have a lot of neutral density to maintain the constant exposure. If you use a color mod and only need a 3 grade, dial in 30 magenta and that is all you get. BTW, constant exposure really only works on middle grey. I always print for textured whites to be the same, and that is not what happens when you change grades on a constant exposure VC module. There the greys stay the same and the whites change which is a pain. Filters are the same thing.

[Brian Ellis]

I used a VC head for many years in my home darkroom and occasionally used a color head at school. Assuming appropriate testing and assuming comparable build quality and other things peculiar to particular units, I don't think there's any major differences in the results obtained or in ease of use. The only advantage to a VC head that I can think of is that the filters in dichroic color heads fade over a period of time so you might have to test more often than you would with a VC head. There may be others that don't come to mind, it's been a while since I used either.

I don't exactly understand ronald's statement that "VC modules have a lot of neutral density to maintain the constant exposure." The VC head I used (Aristo VCL4500) had two tubes, one produced green light and the other produced blue light. In normal operation the green was on all the time at a constant intensity, then contrast was increased by adding blue light. This system could be changed just by moving a switch (e.g. to print with only blue light if you wanted to split print) but that was how it normally operated.

[robc]

either will produce excellent prints. The choice is really dependant on what kind of approach you prefer.

A colour head will allow you to calibrate constant exposure across grades for each paper type. It will also allow you to determine the cross over point of the grades. i.e. the print density at which you adjust exposure time for, before adjusting contrast. You know, adjust print time for a highlight and then adjust contrast for shadows. If the grades don't cross at that value then the concept of calibration is a waste of time since you always need to adjust print time anyway. Making the exact correct densitometric assesment of a print tone is IMO not possible unless you are using a densitometer while printing and if you are not then why bother with calibration.

A VC head will be fixed in this regard so you are stuck with what you've got. Infact you will be lucky if its matched to any paper. However, if your the kind of person who isn't into lots of dubious testing and calibration, then the VC head will work just as well.

Infact the simplest way of printing is to start with white light and add yellow or magenta filtration but not both and don't strive to achieve constant exposure times across grades. Either type of head will do this but if the VC head is of the type which tries to maintain constant exposure across grades then there will be less print time adjustment. However, if you are producing negs of consistent density range then exposure time adjustment should be minimal and predictable with a little eperience.

A colour head is more versatile in the calibration stakes but I question the need for the calibration which is usually not accurate anyway.

[ronald moravec]

I get nice results with my Aristo and V54 tube. The main problem is the actinic light is very bright and the visual is very dim causing very short printing times with a dim image for dodging and burning. Problem was partially solved by adding paper above the diffuser to lengthen the printing time, but then the visual light got even more dim. This give me 20/30 sec at f11 for 8x10.

As far as dichroic filters fading, color head ones may fade in time, but VC modules use the same type of filtration so they are subject to fading too.

A big advantage in the color head is I can use it for color printing. You can`t go the other way.

Now you have all the arguements. If you never want to print color, my choice would be the Aristo 2 tube which I have never used or the new LCD head from Calumet.

I print LF color so I`m not likely to make a choice of a dedicted VC head. I just add yellow or magenta as necessary to the Chromega head if I need a print from a diffusion head which is not often. I really happy with the Ilford filters above the condensers and D2 enlarger. I really see no big advantage to a diffusion head except for neg that has really dense areas that need burning. The diffusion will get light thru more easily. But you can always do selective flashing for a similar effect.

[Jim Ewins]

I achieve a fairly constant exposure across grades by use of both yellow and magenta. (Saunders 4500II) The dichroic is great when printing B&W from color negs. Just dial in enough cyan to offset the orange base and continue as with a B&W neg