HDR For Vibrant Black and White

The High Dynamic Range ("HDR") technique in digital photography has garnered quite a bit of interest in the last year or so.  I am not a great fan of HDR for color images; I have seen so many overdone HDR shots with impossible color and contrast, halos, and exaggerated details that I have shied away doing HDR on most of my color images.   I often shoot several exposures of a particular scene, but I had generally stayed with layer stacking and masking to improve the dynamic range of the final image.

While not pleased with much of the way HDR impacts color images, I have continued to experiment with HDR to maximize the overall impact of my black-and-white images.  It is this approach to making exciting black-and-white photos which I want to share in this article.  (I’ll also be teaching a half-day class on shooting and editing the HDR technique outlines here on May 15, 2010.  Click here for information on that class.)

Over the last year I have developed a workflow for converting my images (I shoot in only in RAW, so all the files come into editing as full-color originals) to black-and-white, using the HDR conversion tools in Adobe Photoshop CS4. I've experimented with some dedicated HDR software, such as Photomatix, but I have stuck with the HDR tools inside Photoshop; it keeps my workflow simple and produces results with which I am very

happy.

My basic workflow when I am aiming for a black-and-white presentation is to first develop a vibrant color image, with excellent dynamic range and good color saturation.  This is where I find HDR to be a helpful addition to my toolbox.

My preferred approach is to start by taking five shots of the scene I want to capture, exposed at -2 stops, -1 stop, no exposure compensation, +1 stop, and +2 stops. This gives me a set of RAW files that maximizes the potential greyscale range.

I select the set of five files in Adobe Bridge and use the "Tools -> Photoshop -> Merge to HDR" menu to send the set of files into Photoshop for initial processing.  You can see the selection and menu in Bridge in the screen-shot to the right.

In Photoshop, I let the HDR processor work the five files in its "Automatic" Response Curse setting, using the default compositing of the files.  I may try some slight tweaking of the overall histogram, but I seldom mov

e it too far from Photoshop's recommendation.  The image will look fairly flat and dull at this stage, as you can see in the screen-shot on the left.  

The next step starts to bring out the real range of the HDR process.  In Photoshop, I use the menu "Image -> Mode -> 16-Bits/Channel" to bring up the dialog box shown in the screen-shot below.  I set the "Method" pull-down to "Local Adaptation" and make sure the Toning Curve & Histogram is fully open.

The histogram will generally show that both the dark data (left side) and bright data (right side) in the merged image do not reach to the limits of the available dynamic range.  I snap each end of the toning curve so that the ends of the curve land on the extremes of the data shown in the histogram. 

The screen-shot to the right shows the curve set to the histogram for this image of Devil's Tower.  The improvement in dynamic range is readily apparent.

Accepting this conversion to 16-bit gives me an image I can begin working on with Photoshop's editing tools.  I will use several general adjustment layers in CS4, always including Levels and Curves, and often adding Contrast, Hue/Saturation, and/or Vibrance as well. My goal is to develop a robust color image with crisp contrast; I find that give me the best starting point for moving into black-and-white.

I generally use a 2-pass Unsharp Mask sharpening approach: once for finer details and once for overall contrast enhancement.  I stay with my usual color fine-detail parameters when I'm working towards a black-and-white conversion, in the range of Amount:100, Radius:1, Threshold:0 up to [100, 1.5, 0].  But while I generally run about [20, 50, 1] for local contrast enhancement in color editing, I find I can push the sharpening a bit higher with

black-and-white, often ending up between [35-50-1] and [50-50-1].  At those levels, it's critical to examine the image closely for halos and other distracting sharpening artifacts, but I am generally able to put in more contrast enhancement than I could with a full-color image.

Once I have a color image that satisfies me for dynamic range, solid color reproduction, and overall sharpness, I apply a Black & White adjustment layer.   Photoshop CS4 provides a wonderfully flexible tool through the 6-channel adjustment process; I find it worlds removed from the days of fighting with the Channel Mixer, Lab conversions, or Saturation layers trying to bring out a useable monochrome image! 

For my landscape images, I'll most often start by applying the High Contrast Red preset.  Having presets as a jumping-off point is one of the reasons I much prefer to do the black-and-white conversion inside CS4 through an adjustment layer rather than in Adobe Camera Raw.  I also prefer to be able to have the monochrome conversion remain editable; I value the ability to work on an image, set it aside, and come back later

to re-visit the toning work I have done.  I find that preset most often give me a good starting point for fine-tuning the conversion. 

I use the "color dragging" tool within the adjustment layer to explore the effect of lightening and darkening the specific colors inside each image.  By placing the tool tip oven an area of the image, and dragging left or right, I can work directly on the most important areas of the image to enhance them in the black-and-white conversion process.

Depending upon the subject matter, it may be necessary to mask off parts of the image and apply two different Black & White adjustment layers to achieve a balance look.  Again, with CS4's current toolset, this is not an onerous task.

These steps result in a image that has decent overall dynamic balance, but I find that images with good overall dynamics can still lack sharp contrast in specific areas.  I have gone back to the classic darkroom tools of dodging and burning to complete my work.  I seldom use the Dodge/Burn tool in Photoshop for my color images, because of the "push to grey" effect the tool produces.  But when applied under a Black & White adjustment layer, the Dodge/Burn tool can produce some very helpful localized adjustments.

My goal is to use the Dodge/Burn tool to enhance the contrast in a specific area of the image.  For example, in the

to the left of the falls in the Willow River, I had an area of small rivulets at the first drop in the waterfall, and I wanted to make those small cascades stand out better.  I selected the Background layer, set the Dodge tool to impact only Highlights, and limited the Exposure of the tool to 10%.  By dragging the Dodge tool over the rivulets with those settings, only the brightness of the water was raised; the mid-tones and darker areas were una

ffected.  I then switched to the Burn tool, set to impact Shadows only, still at 10% Exposure.  A drag of the Burn tool over the same area lets me make a subtle deepening of the darkest parts of the  rivulets without muddying the mid-tones in the. 

By just pushing the dynamic extremes in a localized area, I can move parts of the image that I want to emphasize away from grey tones into more expressive brights and darks.  Obviously, care is needed to avoid completely blowing out the highlights or losing all detail in the darks, but judicious application of the Dodge/Burn tool at very low Exposure settings allows me to progressively build up small adjustments until I get the "pop" that I am seeking.

Here are some other examples of recent black-and-white images produced with the workflow described in this article.  These are all from a trip to the Black Hills in the Fall.

Badlands at Sunset.

Roughlock Falls.

Sylvan Lake.

Finally, while I had been pleased with the black-and-white conversion abilities of CS4 via HDR, I was still not happy with monochrome output until about nine months ago, when two changes came together for me: Roy Harrington's Quad Tone RIP and Hahnemuhle's Fine Art Baryta paper.  Now, with Quad Tone controlling the ink delivery of my Epson 7600, I don't have to fight to get pure blacks and grays - no more muddy, toned prints!  And Fine Art Baryta delivers stunning images with delightful depth and detail.  They make the work in Photoshop HDR worthwhile by producing glorious prints.  They are a great combination, and have let me complete the process of getting exhibition-quality black-and-white images behind glass.