Advanced B/W Conversion No. 2
The Fourth Channel Mixer Layer: Expanding the Dynamic Range of a Continuous-Tone Black-and-White RGB File
At this point you should be fairly clear on the concept that red, green, and blue, the primary colors of light, all have relationships with each other. It’s that interrelationship in the visible spectrum that our eye perceives as “color.” What is unique about black-and-white film is its ability to record the spectral relationships among the primaries of light; it can also record the changes in those spectral relationships and do so in a grayscale.
When you convert RGB to a “gray scale” the way you did in the previous two exercises, you basically created a “digital positive negative.” Negative in the sense that, just like a film negative, it’s the base representation of the photographed experience, warts and all. Positive in the negative-to-print sense, because what we are seeing is what the print would look like if we printed it. The negative is everything. It is the sheet music.
In the next exercise, you are going to create an RGB image with a grayscale tonal range, and then dramatically expand that tonal range without ever leaving the RGB color space. This will be the equivalent of developing a traditional, silver, black-and-white print with a two-step development process.
Step 1: Controlling the Relationship of Red to Green to Blue after Primary Black-and-White Conversion of an RGB File to Extend Tonal Range
1. | On the disc, find the picture of the man with the pipe called BEFORE.TIFF, and do the same kind of basic, three-Channel Mixer, black-and-white conversion that you did in the first exercise. Or, if you prefer, you can use the already converted file ABW 3 CONVERTED.PSD (Figures 5.38 and 5.39). Figure 5.38.
Figure 5.39.
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2. | Just as in the first advanced conversion approach, look at the image with each of the Channel Mixer adjustment layers visible, first one at a time, then all three together (Figures 5.40, 5.41, 5.42, and 5.43). Figure 5.40. Green layer.
Figure 5.41. Red layer.
Figure 5.42. Blue layer.
Figure 5.43. All Channel Mixer layers.
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3. | Make the Red layer active and move it beneath the Green Channel Mixer layer, so the layer order from the bottom up is RED, GREEN, BLUE (Figure 5.44). Figure 5.44.
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4. | Now move the Blue Channel Mixer adjustment layer beneath the Red, so that the layer order from the bottom up is now BLUE, RED, GREEN. |
Looking at the image this way, you can see it with all its desirable and undesirable parts. As with the image of the model on the bearskin, leading with the Red Channel Mixer gives the best overall image, but it wreaks havoc on the man’s face. It’s always best to start with Green, go to Red second, and to Blue third. Only after you have an acceptable base image should you start to correct the rough spots. No two images are the same, and no two black-and-white conversions are, either. Workflow is dynamic, not dogmatic.
Doing the Developer Two-StepIn classic black-and-white printing, one of the best ways to extend the tonal range of a silver print was to split the development process into two steps. You could also do this with the negative, but I found that splitting the print development gave me a better result. The primary reason for this was that it gave me better control; I could see what was happening and therefore had better control of the outcome. The process involved using two developer solutions: Solution A—a metol developing bath, and Solution B—a hydroquinone developing bath. By varying the times in these two development baths, you could extend or contract the dynamic range by at least one entire paper grade. By varying the proportions of metol and hydroquinone, a developer could yield either low contrast (more metol, less hydroquinone) or high contrast (less metol, more hydroquinone). The process was unwieldy and inconsistent (for example, the developer exhausted itself very quickly), but it produced superior prints. |
Note
As a rule, I find that putting the Green Channel Mixer adjustment layer first (working from the bottom up) looks the best 80 percent of the time, Red 15%, and Blue 5%.
The image has two specific problems: (1) The red aspect of the conversion must be balanced for the skin, and (2) The contrast on the man’s shirt must be flattened. Because of this, you will be working with all three Channel Mixer layers, as well as their masks. So what you need is a little insurance.
1. | Create a Channel Mixer layer, select Monochrome, and type 33 into each of the Red, Green, and Blue dialog boxes. Type 1 in the Constant box. |
2. | Click OK and name this layer NEUTRAL. What you just did created a neutralizing layer. The presence of this layer guarantees that no color will bleed through should there be any brush overlap on the individual Channel Mixer layers’ masks. Note If all you’re going to do is change the layer order, or work on one or two of the three layers, you don’t need to create this fourth layer. It’s only necessary if you are going to work on all three layers, as you will do in this exercise. If you create this fourth layer, it must be the topmost Channel Mixer layer. |
3. | Make GREEN the active layer. You want more red than green in the mix to give a smoother skin tone. Make the foreground color black, select a brush at 50% opacity, and brush in the areas shown on the image map (Figures 5.45, 5.46, and 5.47). Figure 5.45. Green before.
Figure 5.46. Image map.
Figure 5.47. After.
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4. | Make RED the active layer. Select the Brush tool, make the foreground color black, and set the opacity to 50%. Brush in the areas shown on the image map (Figures 5.48, 5.49, and 5.50). Figure 5.48. Red before.
Figure 5.49. Image map.
Figure 5.50. After.
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5. | Make BLUE the active layer. Select the Brush tool, make the foreground color black, and set the opacity to 50%. Brush in the areas following the image map (Figures 5.51, 5.52, and 5.53). Figure 5.51. Blue before.
Figure 5.52. Image map.
Figure 5.53. After.
Look at the image after you have done the brushwork in all three channels (Figure 5.54). Figure 5.54. The image after brushwork in all three channels.
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6. | Make NEUTRAL the active layer. Create a master layer, and name it MASTER 1. |
7. | Save the file as a Photoshop file (.psd), and name it STEVE B&W.PSD. |
Note
To see the purpose of the NEUTRAL layer, toggle it on and off, and notice color bleed where the brush strokes on the masks overlapped.
Step 2: Adding Tonality
In traditional silver black-and-white photography, a purely neutral black-and-white print does not really exist. All traditionally made prints, be they silver or platinum, have some degree of color produced by the reaction between the chemicals used in the developing process and the very color of the paper itself. Some people prefer cooler, bluer tones. Personally, I prefer a warm tone for both portraits and landscapes, so I will show you how to create a warm tonality using Curves and Hue/Saturation adjustment layers. You can use the same approach to make a cool-tone image as well.
1. | Create a Curves adjustment layer. From the Channel pull-down menu, select Red. Click the center point of the curve, creating an anchor point (Figures 5.55 and 5.56). Figure 5.55.
Figure 5.56.
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2. | With the arrow keys, move the curve upward to increase the red content. You can move the anchor point from side to side as well as back down. What I came up with for the red aspect of my tonality was this curve and image (Figures 5.57 and 5.58). Figure 5.57.
Figure 5.58.
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3. | Do the same thing in the Green channel, producing this curve and image (Figures 5.59 and 5.60). Figure 5.59.
Figure 5.60.
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5. | Click OK and name this Curve adjustment layer WARM CURVE (Figures 5.62 and 5.63). Figure 5.62. Before adding tonality.
Figure 5.63. After adding tonality.
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6. | Create a Hue/Saturation adjustment layer. Select Colorize. You should see a dialog and image that look like this (Figures 5.64 and 5.65). Figure 5.64.
Figure 5.65.
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7. | Move the Hue slider to the right. The image will start to change color. I stopped at a hue of 38 (Figures 5.66 and 5.67). Figure 5.66.
Figure 5.67.
Hue, in the Hue/Saturation adjustment layer, is a linearized color wheel. If you move the Hue slider completely from side to side, you will notice that when the slider is all the way to the right or to the left, the color of the image is exactly the same. Lower the saturation to 20 and the lightness to –11 (Figures 5.68 and 5.69). Figure 5.68.
Figure 5.69.
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8. | Click OK. Name this layer WARM HUE. All the decisions concerning hue, saturation, and lightness are purely a matter of personal taste. You may like something different from the choices I made here. The trick is to focus on getting the overall tone right. Then you can use layer opacity to dial in the desired intensity. |
9. | I chose to lower the WARM HUE layer opacity to 25% and the WARM CURVE layer opacity to 50%, producing this image (Figure 5.70). Figure 5.70. Conversion completed.
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10. | Make the WARM HUE layer active. Use Cmd-Option-Shift-E/Ctrl-Alt-Shift-E to make a copy of all visible layers and then merge them into a new master layer, name it MASTER 2, and save the file. |
