This process was one of step-by-step refinement, where each step further defined what the end result would be. And the nature of those steps was such that any given step couldn’t be undone at a later stage. This meant that if you wanted a specific look, you had to know how you were going to produce it, step-by-step, from the very beginning, hence, Ansel Adams’ famous teaching that good black-and-white photography required previsualization. Successful previsualization required taking into account every aspect of the process, from film choice to exposure and processing technique, all the way through to the darkroom, including printing papers, developers and toners.
Fortunately, today’s digital processes are infinitely more flexible. Not only do we have the complete freedom to choose black-and-white rendering at anytime, but now we also have very precise control over color contrast after the fact. This is a relatively recent development, even relative to the digital revolution. Because the digital process gives us such great control over every aspect of our tones and textures (can you say, grain?), there has been an explosion of new tools specifically built to help us create any sort of look that our heart desires. But I believe that, after you have the basics of good tonal correction under your belt, it’s managing color contrast that will separate merely average black-and-white photographs from truly great interpretations. And so, color contrast in the black-and-white process is where we focus our discussion for this article.
In the early days of Photoshop, creating strong color contrast started with the technique that you chose because each process assumed different brightness values for the colors in your photograph. Without the sophisticated raw processing tools that we have today, photographers were limited to just a small handful of processes for creating digital black-and-whites. Some of these processes were better at creating contrast than others.
To illustrate, let’s take a look at how radically different this gradient of pure colors is rendered when using two different processes. This gradient was created using the built-in Photoshop gradient preset Spectrum, which creates transitions from the six primary colors, each defined at 100% saturation.
Figure 1: The Gradient Editor and Color Picker over the gradient.
Figure 2: The results of a standard conversion into grayscale, where the cyans, greens and yellows are rendered the lightest tones and the reds and blues are rendered much darker.
These tones come from the lightness values of the gradient colors as they’re defined in the Lab color space, which is modeled on the way humans perceive brightness. Our eyes are most sensitive to greens and yellows, so those colors are rendered lightest. We’re much less sensitive to blue and red, so those colors come with a lower L value in Lab and are rendered darker.
Figure 3: This shows the sRGB gradient colors plotted in the Lab coordinate space in Color Think. The "L" scale for Lightness is the vertical axis in this coordinate system, so colors with higher lightness values appear higher in this space and those with lower lightness values, such as the blues and reds, appear lower.
By using the L values in the standard grayscale conversion, Photoshop uses a model that’s based on how our eyes actually respond to the brightness of different colors. But not all of the processes choose brightness values in the same way, and it’s the brightness values that determine color contrast.
Figure 4: Note that in the top view, the gradient colors follow the outer boundary of the sRGB color space, where they’re at their maximum saturation.
Figure 5: Here’s what happens to the same pure colors when they’re simply desaturated using the Hue/Saturation dialog in Photoshop. Because Hue/Saturation works in the HSL color model rather than in Lab color, the very saturated colors in our gradient are all rendered as middle gray.
Beyond the standard grayscale conversion and desaturating in Hue/Saturation, there are countless other techniques for creating black-and-white in Photoshop. On top of that, there are countless plug-ins out there, each claiming to possess the magic elixir that will make your black-and-white conversions "unique." But by far, the most important aspect of making good black-and-white representations is color contrast. And the raw controls that we now have in Lightroom and Adobe Camera Raw make creating great color contrast a piece of cake.
Let’s take a look at two very different examples of this. Figure 6: First, in this photo of the restaurant front, we have an image that contains colors in nearly every one of Lightroom’s color luminance ranges.
There are two starting points for black-and-white in Lightroom’s HSL tab. Figure 7: When you first convert to black-and-white, the default behavior gives you the Auto mix. The Auto mix generally darkens the greens and yellows and lightens the blues and purples, but the actual mix that you get will be different with every photo. Auto always tries to give you the best color contrast that it can.
Each time I start a black-and-white conversion, I always try both of these options. But, as I said, these are just starting points. The real work (and fun!) comes with working your way down the sliders, using your eyes—and your brain—to create a mix of your own. And it’s easy. The reason why I love these controls is because using them becomes a completely visual exercise. There are no rules, there are no best settings—just your eyes and the sliders. Figure 8: Start at the top, push the Red slider back and forth while you’re watching the image, and find a position for it that makes your picture look the best. Visually. Then mo
ve to the Orange slider and repeat until you get to the Magenta control at the bottom.
Figure 9: As you learn to go through this process, you’ll find that every single photograph will be different. Some photos will need just a few very small tweaks. Others, like the Baja Grill example, can use some dramatic moves to bring out the best color contrast in the black-and-white conversion.
Notice that for this conversion I pulled the Magentas all the way to -100 to give the lettering in the sign effective contrast. At the same time, I pushed the Blue and Purple controls way up into positive territory to bring out the doors.
Figure 10: You might expect the red flower to make a much less interesting black-and-white, but I always like to give my favorite photos a try in black-and-white because results can be a big surprise. In this case, the Default mix leads to a pretty decent black-and-white, mostly because we have such great contrast in the original, with the water droplets and the backlighting.
The Auto mix doesn’t really give us any more contrast, but just lightens things a bit.
Figure 11: As usual, I’m not going to settle for either one of these until I go down through the sliders and find the best color contrast for myself. And, sure enough, pushing things around a little bit reveals a completely unexpected thing when I push the Reds down slightly and then push the Oranges all the way up to +100!
There are colors falling into the Orange zone here, and pushing the Reds and Oranges in opposite directions creates the best color contrast.
The finishing touch for the flower is that little tweak on the Magenta zone up to +50. Take a look at the original color version again, and you’ll see why. The stamen of the flower is pure Magenta. This is a great example of how powerful these raw controls are for manipulating the individual color zones. Being able to push the Magenta colors up in almost complete isolation from the rest of the flower allows me to re-create the contrast that color provides in the original.
So, in my mind, that’s really the lesson in digital black-and-white. There never will be a fixed relationship between any given color and one lightness value. Every photograph will be different. And having eight distinct zones of influence gives you a tremendous amount of control. The most important thing in learning to create good black-and-white conversions is to be willing to experiment and learning to trust your own two eyes.
George Jardine is a photographer, teacher and Lightroom expert. You can read his blog and view a range of excellent tutorials on his website at mulita.com.
Good Contrast: Your Best Starting Point
|Now that I have the flexibility to choose black-and-white as a finished product at virtually any point during the digital process, I try it much more often than I did back in the days of shooting film. Some photos that make good black-and-white conversions are a complete surprise, like the red flower example. You’ll never know until you try. But no matter what, having an appropriate tonal correction before you try black-and-white as an option is always important. Tonal correction means setting the base exposure or brightness, having good contrast, and having solid white and black points. And, for me, having good tonal correction almost always means a somewhat dramatic move on the Tone Curve.|