If the initial image is made on film and then scanned later for digital purposes, the scanned image is also broken into three channels—allowing the same considerations as outlined above. However, if the initial image is a color transparency, keep in mind that the range of contrast encompassed by transparency film falls far short of a black-and-white negative. Two transparencies may be made (one for highlights and one for shadows), or even three (highlights, mid-tones, and shadows) may be exposed to cover a wider contrast range. The most advantageous selection of percentages of each channel can then be made for each part of the image. Of course, with this technique the complexity can become enormous, but it can be done. Please keep in mind that tedium is one thing and fine art is another. How many people think that Michelangelo, Shakespeare, or Beethoven avoided doing their utmost because it was too tedious?
Figure 7-2 is a straight print, showing how much brighter the sky is than the foreground and middle ground of the scene. We tend not to see this tonal disparity because when we look around a scene, the eye automatically opens and closes its own aperture (the iris) to compensate for brighter and darker portions, and the brain further smoothes out the differences. The camera sees the entire scene at one aperture, often with surprising results.
With a good deal of manipulation in the darkroom, Figure 7-2 shows how the tonal imbalance is corrected by darkening the upper portion of the image, then by subtly darkening the edges to direct the eye toward the center, Basin Mountain. The manipulated image is far closer to the way I saw the scene than the straight print.
Figure 7-2. Basin Mountain, Approaching Storm
Note
If people respond favorably to one of my prints, I want them to think that they could have produced the same photograph if only they had been in the right place at the right time. I don’t want any of my manipulations to be obvious.
If the initial color image is made on negative film, which has a far greater contrast range than color transparencies (a range that virtually equals black-and-white negatives), the three-channel breakdown can be applied to the scanned negative. Different scanners, however, have different responses to the orange cast of the color negative, so a great deal of manipulation may be required to get the effect you want. Through careful calibration of your scanner, computer, and printer (or a commercial printer, if you’re using one), you can overcome most, or all, of the potential problems caused by the negative’s orange cast.
For more specific information about filtration via digital means, I recommend consulting other books devoted to that topic.
Infrared Film and Filters
Infrared black-and-white film sees more than the visible spectrum that the eye sees. It goes on into the infrared portion of the EM spectrum, immediately beyond red. Using infrared film can allow the creative photographer some interesting departures from reality. A variety of filters can be used with infrared film to accentuate or subdue the effect that this film imparts.
An infrared filter completely blocks out all visible light, allowing the film to record only the infrared component that is transmitted to the film. Use of such filters with infrared film creates some eye-popping images, both with portraits and landscapes. In portraits, skin tones are rendered in especially milky and unusual tonalities; in landscapes, sunlit foliage often appears blazingly white, as do clouds, while blue skies are rendered intensely black. An infrared filter accentuates this effect to the greatest extent. Of course, since the filter blocks out all visible light, you’ll see nothing if you look through it; it’s as opaque to your eye as a dark slide is for 4 × 5 film holders! But it allows infrared rays to penetrate through.
A #29 dark red filter allows some of the visible light onto the film, creating a nearly complete infrared effect; a #25 red filter allows still more of the visible spectrum through, yet the infrared effect is still quite strong. Going to weaker filters—such as #21 orange, #12 deep yellow, or #8 (K2) light yellow—allows progressively more visible light through to the film, and progressively more subtle infrared effects. As the infrared effect becomes more subtle, the viewer may be unaware that infrared film was used. The leaves on deciduous trees may appear to be bright, perhaps brighter than normal, but almost subliminally so.
I tend to like the effect of infrared film used with the weaker filters or no filter at all. It removes the bludgeon approach that makes it obvious that I’m dealing with infrared film. In general, I want my techniques to be so subtle that they are transparent. If people respond favorably to my prints, I want them to think that they could have produced the same photograph if only they had been in the right place at the right time. I don’t want any of my manipulations—either in exposing the negative or in printing it—to be obvious. In the same way, I don’t want the materials I use to be the issue of interest; I want the image itself to be the issue. So, the strong infrared effects that you get with infrared or deep red filters are generally much too blatant for my sensibilities. Viewers immediately say, “Aha, infrared film!” They are more aware of the film used than the image produced, and I feel that it generally detracts from the intended message.
Filters for Color Images
Filtration for color is not as pronounced as that for black-and-white, but the emotional impact of its subtleties can be every bit as great. Color filtration is limited to altering the color balance in the scene. In addition, filters can be used to change the balance of indoor film to outdoor film or vice versa (Chapter 6). An 85B filter with a
Photographed in the late afternoon under the shade of a nearby ridge, Figure 7-3 takes on a mild yet distinct blue cast. For Figure 7-3, I used a CC10Y yellow color correction filter to neutralize the shift toward blue, giving the image a more natural feel..
Figure 7-3. Aspen Group, Sierra Nevada Mountains
For general color correction, the prime tools are color correction (CC) filters. They are available in several colors—red, magenta, blue, cyan, yellow, and green—and varying intensities of hue in each of the colors. They are nicely color coded by both color and hue intensity as follows: after the letters CC, a number signifies the intensity of the hue and a final letter indicates the color of the filter. Thus, magenta filters come in CC05M, CC10M, CC20M, CC30M, etc., in which two CC05M filters equal one CC10M. Similarly for green, two CC10Gs equal one CC20G. Filters can be combined to reach any desired filtration level and combination. Thus, if you need 25 units of yellow and magenta for filtration, add CC20M + CC05M to CC20Y + CC05Y.
My experience with CC filters shows that for every 25 units of filtration, there is a filter factor of ½ stop, so the 25M + 25Y combination would necessitate a 1 stop filter factor (i.e., open up your exposure one full stop after metering the scene when using those two filters in combination). A full explanation of this procedure can be found in Chapter 8 and Chapter 9.