Saturday, December 15, 2012

Black and White Conversion in Lightroom and Photoshop: Creating Space and Directing the Viewer’s Attention

Tonality in a photograph refers to the distribution of lights and darks across the image. For digital photographers, one of the major decisions we have to make in processing our files is whether to leave the image in color, or convert it to black and white. Sometimes the choice is obvious as you are shooting: you notice that what you are paying attention to is contrast and quality of light rather than color. Other times, the question of black and white versus color comes up as you are processing the file. The prior post in this series on creative composition dealt with how and why to use color as a structural element. Today, I’m going to follow up with some ideas about when to make an image black and white and how we might use the range of grays available to focus the viewer’s attention and enhance the photograph’s depiction of space.

August Sander

Irving Penn

From image to image, the range of grays can be quite variable. The measurable distance between the darkest dark and the lightest light is contrast. Depending on the process, paper, and desired effect, that range can be broader (Irving Penn, above) or more narrow (August Sander, above.) 

W Eugene Smith

William Klein

Andreas Fenninger

The histogram is the graphical measure of how tones are distributed between black and white. There is no ideal histogram. There can be a bias towards the bulk of the information being in the shadows (low key), or in the highlights (high key), or more evenly distributed across the image. The histograms for the three images above are immediately below.

The nature of the transition from one tone or value to the next is another variable. That transition can be smooth and gradual (as in the Jock Sturges, below), with one tone slowly merging into the next, or it can be abrupt and quick (as in the Bill Brandt, below.) In the Sturges, the gentle inflections of tonality contribute to the overall elegance and grace of the image, while in the Brandt portrait of the painter Francis Bacon, the near absence of mid-tones and very abrupt transitions from lights to darks support an impression of unease and dissonance.

Jock Sturges

Bill Brandt

These three aspects of light and dark -- the breadth of the tonal range, how the tones are distributed, and the transition from one tone to the next -- constitute our tonal vocabulary. We can use this vocabulary to set the emotional pitch of the image. It also can be used to identify the subject, provide the means by which the viewer's eye transverses the image, and and either help or hinder the suggestion of depth in a photograph.

Joan Fontcuberta

A photograph is a two dimensional representation of a three dimensional space. The careful separation and placement of tones helps support the illusion of space and depth. When we have an image with the same tone appearing in what are actually different planes in our subject, it tends to push those planes together, destroying the illusion of depth. To increase the sense of space in a black and white image, try to pull like gray tones apart. In the Joan Fontcuberta above, notice how the each plane of the mountain-like shapes gets lighter as it recedes, supporting the illusion of depth. The way you separate like tones will depend on the image itself, but the general principle is to create depth by emphasizing the differences among adjacent tones when those tones represent separate planes. 

Ensuring that there is detail in both the highlights and the shadows supports the illusion of depth. When we look at the world, our eyes are able to discern greater detail in dark areas and light areas than a file straight out of the camera will show. Especially with a high contrast subject, the file will often require some degree of massaging to resolve highlight and shadow detail.

Irving Penn
Irving Penn

When we have an image with large undifferentiated areas of light or dark, as in the upper Irving Penn, these areas tend to be perceived as shapes. Shapes are read as two-dimensional. Detail in the highlights and in the shadows will minimize any area that might be read as a shape, supporting the photograph’s depiction of space. In the Penn portrait of Miles Davis, the face looks fully round because there is full detail in the nose, cheeks, lips and forehead. Notice that shadow areas like the lower jaw tends to flatten out without detail in them. (For those of you who have taken one of my Photoshop classes, you know that not all of the detail visible on the monitor will be present in a print. This is why we want to check the info palette as we work. The range of printable detail is 243-20, less than the complete range of the histogram.)

Jock Sturges

We support the illusion of depth through our control of tonality. We also use tonality to direct the viewer’s attention. The area of maximum contrast tells the viewer: look here first. In the Jock Sturges immediately above, the area of maximum contrast is the head and hair against the brightest part of the background. In other posts, I’ve written about the significance of creating a path for the viewer’s eye to move through the image. Here the primary path begins at the head and moves down the left side of the figure (as we are facing the image, her right side) and then back up the other. Notice that your eye does not get pulled down out of the bottom edge of the image, but instead pauses at the highlight on the knee. That highlight acts as a form of visual punctuation, causing one's gaze to slow down, and thereby provides the mechanism by which the viewer returns to the upper part of the figure. Take a look at the two photographs by Shomei Tomatsu below. To which part of the image is your eye immediately drawn? Where does it go next as you explore the image? Where does it end up?

Shomei Tomatsu

Shomei Tomatsu

With all of this in mind, I’d like walk through two specific examples of the black and white conversion process, addressing the aesthetic ideas behind the series of technical decisions that were made in adjusting the files. Both of these images have been graciously contributed by photographers with whom I have been working over the past year, sometimes concentrating on how we can get the most out of our images through the black and white conversion process. The final stage of each image is below. The store window filled with dots and reflections was taken by Katherine Bristor. The stark building in the landscape is by Debra Bilow.

Katherine Bristor
Debra Bilow

Starting with Katherine’s image, the point of interest is the spatial ambiguity combined with the pattern which extends from the figure to the ground. Once you have an idea of what the photograph is about, all adjustments should be made with the purpose of enhancing these aspects of the image. 

Just below is the file as it appears right out of  the camera. The RAW file is obviously dark. The exposure has been thrown off by the highlights on the windows in the background and on the mannequin's forehead. The histogram shows the file is properly exposed to the right -- it is just that the contrast of the scene is too great for the camera's sensor to record in a single exposure. With a tripod, HDR exposure technique would have provided a better starting point, nevertheless, after an initial set of adjustments in Lightroom's Develop module (lower image), we can get a clearer sense of the possibilities for this photograph.

There are some interesting aspects to the color of the image at this stage. One option would be to play the "barely there" color off of the undersaturated buildings and stark pattern of the black and white dress. Another option would be to accentuate the graphic pattern of the dress and the floating dots -- a tonal approach rather than a color approach. To preview what this might look like, an initial black and white conversion was made in Lightroom's HSL tab.

The tonal range is compressed, which is minimizing the suggestion of depth; however, I do like how the black spot painted on the mannequin's cheek takes on prominence as the focal point in the black and white version. And that observation suggests the approach. Connect the dark dot with the pattern of larger sized dots that are floating across the image. Compare that pattern with the smaller scaled pattern of dots on the dress and on the handbags. Enhance the multiple layers of depth by pulling the dots out of the background. On the left side in particular, you can see how the dots are merging in tone with the sky and building.  

The next stage of adjustments occur in Photoshop. Many of the adjustments on their own are fairly subtle, but they do have a cumulative effect. To better see the difference, compare the set of images below. The top image is right out of Lightroom. 

The middle is after a series of curves adjustments in Photoshop. Two curves adjustment layers with layer masks are used to bring out the pattern of dots against the building on both the left and right. Another masked curves layer is designed to enhance the pattern on the dress and handbag. The overall effect is an improvement; however, the dots in the sky are still too close in value to the sky itself. The mannequin and dots on the right appear to be in the same plane because they are so close in tone. 

The bottom image shows the effect of using a burn and dodge layer to lighten the dots against the sky in the upper left, as well as darkening the very top part of the sky. The white dots and building on both sides were also darkened a little, so as not to compete with the pattern on the figure. This also helps to establish that the mannequin and the dots are not in the same plane.

Below is a comparison of the initial black and white conversion to the final adjusted file. Notice how much more fluidly your eye moves through the final version of the image as compared to the initial black and white conversion. In this kind of image, we want to invite the viewer's eye to look everywhere, so we need offer something of interest in every section of the image. 

It always helps to have an idea of what an image is about before committing to a processing strategy. In Katherine's store window display, the idea was to create an image with an active surface, so that the viewer's eye would move laterally across the surface of the picture as well as separating the various planes of the image (buildings, mannequin, and floating dots), so that the sense of depth was enhanced as well. The processing decisions built upon the complexity that was present in the original photograph. 

A different image poses a different set of problems and possible solutions. In Debra's picture below, the compelling aspect is the contrast of the geometric shape of the structure and the gentle curves of the landscape. I'd like to show the structure as both separate from and integrated with the landscape. 

The strongest aspect of the color is the cyan reflection of the sky against the dark red of the building. Those are complementary colors, so having them in proximity could be the basis for an idea about how to use color in the image. However, the dominant color, green, doesn't play into that combination. If the sun were shining on the building, so that it appears a bright red, there might be a way to use the color, say a small area of intense red against a much less saturated ground . But as it stands, this image is more about form and structure than color. So let's see what it looks like in black and white.

This (above) is the default black and white conversion in Lightroom. The shape of the building seems accentuated against the lighter sky. 

After adjusting the sliders in Lightroom's HSL tab (above), greater tonal variation is achieved in the foreground. The HSL tab converts a color difference to a tonal difference, and is very useful in separating like adjacent tones in a black and white conversion whenever a color difference in the original file is present. In this case the greens are pushed darker while the yellows lighter. Expanding the tonality within the grass expands the illusion of depth in the image. 

Additionally, the blues are brought down, darkening the sky and emphasizing the gradated arc there. This provides an additional curve which relates to the other curves in the image. We did lose the glow of the window, so that is something to be addressed later with a local adjustment. 

A fine tuning (above) of the settings in the Basic Tab heightens the overall contrast and brings out detail in the grass.

Local adjustments (above) are made to address specific sections of the image: enhancing the structure of the building and lightening the window. Some of the shadow areas in the foreground are also lightened. We want to have the building be as dark as possible, while at the same time still being able to discern full detail: if you click on the image to see a larger version, notice that each clapboard is fully visible. Lightening the window connects that element to the rectangle of the frame itself. As a compositional element, the window acts as a foil to the building and sets up the following visual analogy: the window is to the building as the building is to the frame itself.

The final image (above). After all local adjustments are made, a little fine tuning of the Basic tab settings is sometimes in order. Below we have the original RAW file compared to the final black and white conversion. Below that is the initial black and white stage compared to the final version. All adjustments were made in Lightroom.

In the final version of this image, we have a nice s-curve of light leading from the foreground to the building. We have asymmetrical curved elements surrounding the perfect geometry of the building. These aspects were latent in the color version of the file, but they have become much more explicit after the black and white conversion. It also seems that the building feels more a part of the landscape in black and white than it does in color. 

Every adjustment we make in processing a file is made with some goal in mind. We might be supporting the illusion of depth. We might be emphasizing shape. We might be linking two elements together, or pushing them apart. We might be directing the viewer's eye. Sometimes color helps in articulating the idea of the image; sometimes tone is more effective. As you work on your files, think about making adjustments, whether they be color or tonal, in a purposeful way.

This is the seventh installment in a series of posts on composition. The entire series is archived on the "For Students" page, accessible at the top menu. Check there for the prior posts in the series, as well as for future installments.