Caught in the Web
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An Occaisional Series of Interesting Items found caught in the threads of the World Wide Web.

Those of us who make prints from transparencies - especially Ilfochrome (neé Cibachome) prints - often have trouble getting the contrast range of the image on the slide to fit into the much smaller range possible on the paper. Normally this means that something has to go. There are many techniques for contrast reduction available to the conventional photograph maker with wide applications. These range from careful exposure and development of the original image to yield one with exactly the right contrast to print correctly, through the use of specially formulated low contrast print developers to the use of masks. These are usually "permanently" made on conventional film but photochromic glass can be used for "temporary" masks. The following article, originally written by Barry Sherman, deals with the subject of Masking. I have reproduced and "Anglicized" it with his kind permission.

Masking 101

There are lots of different techniques. Mine are derived from a section in a book by Peter Krause and Henry Shull entitled "Complete Guide to Cibachrome Printing", (published in 1982 in the USA by HP Books - from Fountain Press in the UK but long out of print), from a book and video tape by Bob Pace (custom Ilfochrome and dye transfer printer), from a workshop on Ciba masking offered in the USA by Charley Cramer and from the Ilford booklet on the subject (available free from Ilford - catalogue no. 15867). Kind of a mish-mash of techniques. So everything I say here reflects my own ways of working and is strictly "in my humble opinion".

Bob Pace's book and video may be obtained from: Bob Pace 2823 Amaryllis Ct. Green Valley NV 89014 USA.

It has lots of good information, although I've come to think that he over-tests and that his strongly sensitometric-based technique yields results little better than more seat-of-the-pants ways. NB: What I'm about to describe will probably sound very complicated. In actual practice it isn't. Making a contrast reduction mask typically takes me maybe 20 minutes, including setting up the trays and cleaning up. Making the print typically takes 6-30 hours depending on degree of difficulty, how important it is to me and how many copies of the final print I want to make and how obsessively perfectionistic I happen to be feeling at the time. So making the mask is a pretty small part of the entire process.

Ciba Papers

I don't find the various contrast grades within Ilfochrome papers terribly useful. They don't seem to me to span enough of a range. I have far better control using masks and can print a far higher contrast original than I can using Ilfochrome low contrast paper. Others, however, have different experience. I prefer a print which has contrast similar to that of a C print only with the Ilfochrome saturated colours. Others like a little more contrast. We all have our own preferences. I recently learned a discouraging fact about my preferred paper: Ilfochrome classic RC Pearl finish. I noticed some unpleasant "mottling" in a smoothly toned area. Lots of investigation led me to a local Ilford rep who was really honest. He told me that this is a known defect in some batches of RC Pearl paper and they're working on eliminating it. I tried making the same print with other emulsion batches and the problem didn't happen. But it's difficult to feel comfortable buying large quantities of large Ilfochrome Pearl paper now that I don't know whether it'll be defective. The rep said that he's never heard of the problem with the glossy finish RC, nor with the super-glossy polyester paper, nor could I replicate the problem on those emulsions.

[ NOTE: Since I wrote this, several years ago, Ilfochrome has dropped the contrast on the Pearl finish to where some of my images won't print even unmasked. So I've switched to the high contrast polyester super-glossy material, CPS.1K. I also investigated Fujichrome type 35 super-glossy as I've concluded that in most respects the new R3 materials are superior to Ilfochrome. All respects, that is, except for longevity and colour saturation, and Fujichrome is supposed to be at about 70% the longevity of Ilfochrome. As a result I now use both Ilfochrome and Fujichrome, depending on which works best for a given print. Fujichrome is somewhat lower in contrast than Ilfochrome super-glossy but does still require masking at times.]

What is a contrast reduction mask?

Put very simply, a contrast reduction mask is a b/w negative which is produced from an original and is sandwiched with the original to alter contrast. Being a negative it will be dark where the original is light and light where the original is dark, thus lowering contrast. Masking can get quite sophisticated, however. You can take a negative contrast reduction mask, contact print it onto another sheet of film, getting a positive, and use this as a contrast-increasing mask. You can use either type of mask with b/w and colour negatives as well as with colour transparencies. I have also done contrast masking with both colour and b/w negatives. Why mask with b/w negs when we have different contrast grades, variable contrast papers and different contrast developers available to us? With a little care it is possible to produce masks which are clear except for certain areas, where they'll affect contrast. Localized contrast control. This, along with flashing and bleaching, helps to bring to graded papers the level of contrast control available to those who use variable contrast papers. You can vary the overall
density of the contrast reduction mask so that it reaches down to the mid-tones or even to the shadows, thereby varying where contrast will be altered. In addition, you may at times make a mask which is used in making the final mask. Several generations can be involved. More on this later.

Masking equipment

Equipment can be simple or fancy. Basically, the equipment, if any, is used for registering the original and the mask.

* Light box and loupe. After producing the mask you lay the original and the mask on a light box and use a loupe to line them up, taping them together when they're right. Mylar tape, available in better photo shops works well for this. This can just about drive a person crazy, especially in 35mm where not only do you have to worry about getting them lined up perfectly, you also need to worry about removing every last speck of dust. (Dust is less critical in large format as it's enlarged less.) A friend who works in 4x5 opines that this technique works just fine for him, while it drove him nuts when he worked in 35mm. The larger images are easier to register. Personally, I'm lazy and am delighted to have Condit pin registration equipment.

* Condit Pin registration equipment. This is a set of equipment comprising a punch, contact print frame and negative carrier. The punch punches little 1/16" holes in the edges of 4x5 or larger film. These holes are used to align the original and the masking film in the contact print frame and in the negative carrier. Models are made for most of the standard large format (4x5 and larger) enlargers: Beseler, Omega, Durst, Saunders, DeVere ...

Also, it's not necessary to order all the equipment at once. The largest expense is for the registration negative carrier. This is a fancy device which will actually allow one to remove the negative carrier, change masks, re-insert the carrier and make a second (or third or fourth) exposure on the same sheet of paper without losing any sharpness. But if one just wants to use contrast reduction masks then it'll work just fine to only buy the punch and contact print frame. After drying the mask, it can be put back on the pins of the contact print frame along with the original and the two can be taped together.

Silverprint, in the UK, sell a registration punch based on a standard office punch. This is designed for large (12 x 12 and upwards) sizes.

* Wess Plastics makes some equipment (a duper and a registration punch/slide mount system) that some people have used with some success for working with 35mm. Others report that precision is insufficient for serious use. The duper uses the rectangular sprocket holes of the film to register it with the masking film. The mask is exposed as it would be with any masking equipment, making a contact print under the enlarger light source. After processing the masking film, Wess registration slide mounts are used to carry the registered mask
and original.

These mounts also use the sprocket holes and precisely sized rectangular projections to register the two.

In the UK, 35mm registration slide mounts are also available made by GePe, and 6 x 6 and 6 x 4.5 are available made for Hasselblad.

Materials

* Film. Kodak Pan Masking Film used to be the standard. But it's been discontinued.

So I now use Tmax 100. It requires different handling to produce the unsharp masks, but I think that it works just fine. Only problem is the amount of effort required to remove the purple stain, which is pretty tedious. Why Tmax 100? Because I have it lying around so it's handy. Roll films such as Tmax 100 are easiest to use if one is working with roll film originals and using the Wess equipment to aid in registration. Roll film can be used for masking 35mm or medium format. Tmax 100 is certainly an option here. FP4, both in sheets and rolls, is popular
as well.

Kodalith. Kodalith high contrast film is used for highlight protection masks. More on this later. Very useful stuff to have around. One technique made easy using large format and registration equipment is "dye dodging" in b/w printing. You register a blank piece of film with a b/w negative and use spotting colours to paint over areas on the blank piece of film where you want the print to be a little lighter. Kind of like dodging using impossibly small dodging tools. I like Kodalith for this because the anti-halation backing rinses off much more easily than with more conventional films like Tmax 100. Just pop an unexposed sheet in some fixer for a few minutes and it's clean and clear. But I digress ...

Continued next time