An Introduction to Selective Masking Part I

A Method for Total Control of Dodging and Burning in Analog Printing

By Alan Ross Back to

(Figure 4) Burned Church, Las Mesitas, Colorado (Figure 4) Burned Church, Las Mesitas, Colorado

No matter how adept we might be at utilizing local printing controls such as dodging and burning, or using multiple contrasts, we sometimes still find ourselves faced with an image which either defies our best efforts, or makes us really strain to get things to come out right.

Have you ever wished you were an octopus? I’ve had several images where I had to have an assistant dodge one area of a print while I dodged another. Have you ever been frustrated trying to deal with a little part of an image, an important one, that’s just too small to even get a dodging wand into, much less control it accurately? If you have to make more than one or two prints of an image, do you have trouble getting the dodging or burning or bleaching on print number two to be the same as print number one? If you’ve experienced any or all of these aggravations you may feel you need the services of a shaman, but the following techniques, at least for me, produce more predictable results.

Having been charged with the responsibility (and pleasure) of printing Ansel Adams’ Yosemite Special Edition negatives for over 36 years, I have had to dedicate a great deal of time and effort in the cause of control and consistency. Over the years I’ve evolved a technique I have come to refer to as Selective Masking. I use the term “selective” because it is a physical, hands-on method, which has no relation to the purely photometric process of “unsharp” masking so popular in some circles in recent years. In its basic form, it’s not techno- anything; it simply is a means of solidifying your own dodging and burning preferences into a “package” which remains absolutely constant from print to print. You can change your mind about how you want that package to perform; you can dodge and burn in greater detail than with traditional methods and with absolute consistency from print to print.

Selective Masking techniques can be used to lighten or darken as many large or small areas of the image as desired, and advanced techniques can be used to replicate the effects of smooth, broad—area burns such as the method commonly used to gradually darken a sky toward the top of an image. The beauty of the technique is that it is easy and inexpensive, and it allows complete personal expression. Nothing is etched in stone. If you make an area too light, you can adjust it. If the area is still too dark, or if something else isn’t quite right, you can adjust it. In this article we’ll cover the basics of the method to lighten and darken specific areas. In a subsequent article we’ll cover the more advanced techniques for making graduated broad-area burns, and a third article will cover techniques for making “built-in” multiple contrasts on variable-contrast paper.

(Figure 1)

How it works:
The function of a mask in Selective Masking is to modify the amount and kind of light that strikes the negative without itself becoming image-forming. This requires use of a special negative carrier that allows a piece of diffusing material to be in contact or near contact with the top of the negative, thus allowing us to place various light-blocking materials on the light-source side of that diffuser without their having any clearly defined effect on the qualities of of the image. If you lay a negative emulsion down on a light table and place a piece of 1/8th or 1/16th-inch thick diffusing/translucent- Plexiglas®, or equivalent acrylic diffuser, on top of it, you will see a fuzzy image of the negative through the plexi. If you tape a piece of drawing material such as tracing paper or artists’ matte Mylar on the surface of the diffuser facing you, you can use an ordinary pencil to add density to the “package.” Wherever you add density, you will lighten that exact area in the print. The more density, the more you lighten. If you cut a hole in the Mylar, you will be decreasing the density in that area of the package since the Mylar itself adds some density. Wherever you cut a hole, you let more light strike the negative, and you will be darkening that area in the print. This is the essence of the technique. A few cheap tools, a little bit of practice, and you’ll soon find yourself in absolute control over aspects of your printing you never before thought possible.

Since the use of a diffuser over the negative is essential, it does mean that the technique cannot be used with any optically-focused light sources such as condenser or point-source systems. It works perfectly well with any diffusion light-source or for contact-printing.

(Figure 2)
(Figure 3)

What you need to make it work:
1) A diffusion enlarger. Any kind will do: dichroic color-head, cold-light and variable-contrast heads. If you use a cold light and can easily remove the diffuser from it, do so. The diffuser over the negative can serve as the diffuser for the cold light tube. If you have a colorhead or if it’s difficult to remove the diffuser, don’t worry about it, you’ll just lose a small amount of printing speed. If you make contact prints, you can replace the glass in your printing frame with plexi.

2) A special negative carrierthat incorporates a diffuser in its upper half. This can be as simple as a sheet of diffusing plexi, hinged to a sheet of picture glass with tape; the two pieces sandwiching a sheet of black paper with a hole cut out to frame whatever negative size you want to use. I have several of these. I also machined a recess in the top plate of each of my Beseler carriers so that a piece of 1/16th-inch thick diffuser nests down flush with the top of the carrier, less than half a millimeter above the negative. The bottom of the carrier, being glassless, helps keep dust problems to a minimum. I use 1/8th-inch thick diffusing plexi (available at most glass and mirror shops) when a cold light tube is not already diffused. With dichroic or VC heads which have integral diffusers, I prefer to use 1/16th-inch thick plexi for negatives 4×5 and smaller. This thickness (0.062″) isn’t too easy to find in many areas, but a well stocked, “big city” plastics-supply company should have it and be able to cut it to size. The thinner plexi affords a bit more precision for 4×5 and smaller negatives since the image viewed through the diffuser is not quite so fuzzy as with the 1/8th-inch material. Both will work. The “plexi” I use is like what is used in light tables as the diffuser for the lights and has an industry-standard designation of “2447”. An internet search for “Plexiglas 2447” should turn up lots of results.

3) A light table in the darkroom. You will be using it a lot, so it should be readily accessible but not in the way. It only has to be large enough to illuminate the whole negative.

4) A variety of expendable drawing materials such as artist’s vellum, matte Mylar, tracing paper, etc. The only requirements are that they be trans- parent enough to see a distinct image through them, and that they can be drawn on, preferably with a pencil. My favorite material is the matte- surfaced Mylar available at most art-supply stores. This material has very little density of its own and has a perfect surface for penciling. It is available as single or double-side matte. I like the double-side. Tracing paper or vellum has more density than the Mylar and is a good choice when areas of the image need significant burning. These will be your masks. They can be used singly or in multiple layers.

5) A variety of pencils and small markers. I use 2H, 4H and Stabilo “All” pencils most of the time, but regular #2 pencils work just fine, and fine point

“Sharpie” markers also come in handy. A nice thing about using pencil is that it can be erased if you go too far. I find that the formable, gray eraser tends to smear a bit less than other kinds. The “All” pencils are great, they write on any surface, like a china marker, but they are water soluble, so penciling can be removed easily with a moist cotton swab. I particularly like the #8008 “graphite” Stabilo, but the 8046 “black” is good too. Colored pencils and markers (yellow and magenta and/or green and blue) can be used to make subtle contrast adjustments when using variable-contrast papers. I recommend against using “highlighters” since their colors can fade easily. They would work fine in the short term.

6) X-Acto knife for cutting out areas of the drawing material over areas needing to be burned. A pair of pinking shears can also be useful for cutting a feathered edge.

7) Tape.Since the negative has to remain in position relative to any mask, it’s important to keep the negative from moving around in the carrier when removing it and replacing it in the enlarger. I like the Scotch® MagicTM Removable tape for securing the negative in the negative carrier. A heavier tape such as white Artist tape or black photo tape is good for affixing the drawing materials to the negative diffuser.

(Figure 4) Burned Church, Las Mesitas, Colorado
(Figure 5)

The opening figure, Burned Church, Las Mesitas, Colorado was done with a 120mm Nikkor-W on 8×10 film with a #12 yellow filter.

In spite of the filtration, the sky still needed a fair amount of burning to get the effect I had in mind. The trouble was, if I just burned the sky down without dodging the church, the top part of the building would get darker, along with the sky, while the bottom would stay light. I could wave a dodging wand around in the upper part of the building during the basic exposure, but I certainly would have a tough time being very thorough or consistent. Even with my experience I would consider my chances of getting a good print pretty much a matter of luck.

Selective Masking, however, made a “non-problem” out of the issue. It was a simple matter to add a slightly graduated amount of pencil density to a Mylar mask to completely compensate for the burn I gave to the sky. There were still a few too-bright clouds and a hotspot near where the walkway meets the building which would all be pretty easy to hole-burn for each print—but why bother? By cutting out small areas of the mask where I wanted to darken the print a bit, I was able to incorporate the needed local burning into the basic exposure and broad sky burn.

(Figure 6)
(Figure 7)

Figure 4 shows the finished print, made with the final mask in place. Figure 5 shows a print with the identical exposure as Figure 4, except that the finished mask was replaced by a blank sheet of Mylar. Figure 6 shows the finished mask itself. Note the small cutout for burning the round window over the door. Normally such a tiny area would be quite difficult to hole-burn successfully, but the mask took care of the problem effortlessly.

Figure 7 shows a cloud burn being cut out of the mask—first, draw an outline of the area to be cut out, then place a piece of card between the mylar and plexi before making the cuts.

Limitations and Hints
Areas in an image of smooth, textureless tonality such as a clear sky are difficult to mask successfully. Any unevenness in the penciling has a good chance of showing up as unevenness in the print. It is sometimes helpful to smudge the penciling with a cotton swab or tissue to smooth out uneven densities on a mask.

Sometimes it is hard to see areas of a negative through the diffuser well enough to accurately pencil or cut out a particular area. If you turn the negative carrier upside down and hold it over a light table, you can see every detail of the image. Then, when you place the tip of a sharp pencil on the back, Mylar, side you can see it well enough to get a better idea of the desired location.

The smaller the negative, the more difficult it is to take advantage of Selective Masking. I have used the technique with 35mm film, but only rather broad areas can be dealt with successfully.

Just because a mask may have been deemed right for one printing doesn’t mean you can’t or shouldn’t burn or dodge in the traditional fashion if you feel like it. If you feel that a mask is no longer creating the effects you want, make adjustments or start over. When I need to print the negative again I put the carrier on a light table and position the mask over the negative visually. Highly precise registration is not necessary!

If you cut a hole in a mask and decide that it is either too large, or is in the wrong place, you don’t necessarily have to start over. Try adding a blank sheet of Mylar and pencil lightly over the irksome hole.

When I want to add some pencil density to an area I’ve already penciled, I make the new pencil marks run in a different direction from those made before, creating a sort of crosshatched pattern. In this way, I can tell how much of the target area is newly penciled.

Have Fun! Be Bold! The biggest downside to this technique is that it affords so much control that it is difficult to know when to stop!

About the Author

Alan Ross
Photographer and master printer Alan Ross has been Ansel Adams’ exclusive printer for over 36 years. His experience includes operating a commercial studio with projects ranging from ad campaigns to murals for the National Park Service. Since 1993, he has devoted his energies to his personal work, teaching and work for select clients, including Boeing, Nike, IBM and MCI. His photography hangs in collections and galleries throughout the country and internationally, and he has lectured and led workshops in locations from Yosemite to China. For a more in-depth discussion of Ross’ masking process, visit his website,