HDR and the Zone System

High dynamic range (HDR) photography is popular with some, and anathema to others. For some, HDR yields an artificial, over-processed look. Others like that HDR look. I am not here to discuss any of that. Rather, I’m here to outline a specific HDR method that can help you deal with some extreme range subject matter. In previous pages, I’ve explained how a single RAW file from a pro-grade camera can deal with up to 2 stops of highlight elements without compromise to mid-tones. There are occasions with even more separation between Value V and specular highlights or direct light. In situations like this, HDR methods can be of use. Here, I propose a simplified approach to HDR that can easily manage images in which there are elements at Value XII or higher.

The method requires both Lightroom v4 and Photoshop CS6. In my case, I’m using LR 4.4 and PS CS6 at the latest versions available at the time I am writing this. Elsewhere on this site, I’ve posted about Adobe’s amazing HDR technique that LR and PS now support.

As I have clearly pointed out in this sequence of pages, getting Value V right is of the essence of the Zone System. Perhaps, more specifically, one should make a decision about which Value of which element in the scene should be mapped to which Zone. Placing Value V on Zone V is one approach. Dealing with extreme highlights by placing Value V on Zone III is another; later we can use levels and curves to restore Zone III in the RAW file to Zone V in post.

With HDR, we are again faced with the question of what Value to place on what Zone. Suppose we have an instance in which Value V is 7 stops below the Value of highlight elements with direct lighting or specular highlights; that is, they are at Value XII. Let us address this significant span with an HDR approach. Find Value V by metering the scene and set your camera for manual exposure at a setting that will place it on Zone IV. The highlight elements will fall on Zone XI, which will be blown out in any current DSLR. Now set your camera as appropriate to capture one image with 0EV of exposure compensation and one with -2EV. You can get more, if that’s the way your camera works. You’ll just use these two: 0EV and -2EV. In the -2EV exposure, Value V will be placed on Zone I, and Value XII will now fall on Zone IX. We can now capture detail and texture in these highlights.

Selecting images in LR

Selecting images in LR

Bring these two exposures into LR4. If necessary, use the Develop module to correct any lens problems (like chromatic aberration and distortion). Do not alter any of the exposure settings. Select both images and right click. In the context menu that opens up, select Edit In…/Merge to HDR Pro in Photoshop. In the Photoshop window that opens, use the 32-bit mode, and move the slider for white point to the right so that highlights in the image are not blown out.

PS 32-bit HDR Pro window

PS 32-bit HDR Pro window

When the file opens in PS as a 32-bit RGB result, select Cmd-S or do a Save from the File menu. This will put a 32-bit TIFF back into the original LR folder. Do nothing to the file in PS. All edits will be done in LR.

Just Save

Just Save

The resulting 32-bit TIFF has an almost unbelievable 20-stop range of exposure control in LR. That’s right: 10 stops up and 10 stops down. LR provides a curves adjustment tool in which you can shift the mid-point (Zone V), and this case, we’ll want to push it downwards; that it, identify Zone III with the mid-point of the curve. We can then pull up the Values for the mid-tones, while maintaining highlights at their, now, Zone VIII location. By also using the exposure, shadow, blacks, and related sliders, it is straightforward to bring a known reference surface in the image back to a desired Zone; e.g., a Value V surface to Zone V.

Here is the original 0EV RAW file with a simple B&W conversion.

0EV capture

0EV capture

And here is the HDR result processed as just described, with additional clarity, and with a B&W conversion to emphasize the red-orange-yellow color tones of the bush in the foreground. As you may notice, it was shot with the sun immediately behind the bush, low and near the horizon. The original impression was of a burst of fiery yellow light from the tone of the autumn leaves backlit by the sun.

HDR result processed with Zone System method

HDR result processed with Zone System method

This is a 100% closeup to show that there is good texture in the leaves, not a bad trick for an HDR process that can be plagued with ghosting due to any movement of leaves in the slightest breeze.

100% close up

100% close up

The following image was handled in an identical fashion. It may not look like it, but it is a wedding photograph from a shoot my wife and I did last year. The tent in the distance is for the reception afterwards. You may also notice a bower this side of the trees in front of the house. I took this HDR shot at the entrance to the groom’s place for the album. I have done the usual trick of bringing up the mid-tones with a curves layer after just getting the highlights in the clouds to a printable level. I have further emphasized just the “Freedom Ranch” sign on the cross-beam with a touch of further exposure increase.

Wedding photo

Wedding photo

As you can tell from the shadows, the sun is immediately overhead. High noon in old Colorado. The following closeup is to demonstrate that there is still reasonable texture and detail in the rusted metallic cowboy on the shadowed side of the gateway.

Cowboy 200% detail

Cowboy 200% detail

Here is one last example, a classic of Colorado, the aspen at Golden Gate State Park. This image was treated in exactly the same fashion as the previous two; that is, a 0EV and a -2EV capture, both taken through PS HDR Pro and then edited as a 32-bit TIFF in LR to recover the mid-tones.

Colorado Aspen, HDR

Colorado Aspen, HDR

This was shot straight into the sun, yet there is a good deal of detail and texture in the shadows. In fact, the problem is not to bring out detail in the shadows, but rather to avoid the resulting artificial look: we shouldn’t be able to see into the dark very well if the sun is in our eyes.

Anyway, the point is that judicious use of HDR techniques, while maintaining a grasp on proper Zone exposures, can yield excellent and natural results. And that’s it.

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