The more time I spend in my photography pursuits, the more I appreciate cameras that capture and photos that exploit their maximum dynamic range potential. Digital cameras have undergone dramatic improvements over the last 12+ years, but they still don’t come close to the human eye’s dynamic range capabilities. By some estimates, the human eye can distinguish up to 24 f-stops of dynamic range. Higher end DSLRs such as the Nikon D800 by comparison, can capture up to a theoretical max of 14.4 f-stops of dynamic range. The usable dynamic range of most DSLRs, however, is closer to 5-9 f-stops, considering the impact of noise, which can render some of the DSLRs’ f-stop range impractical to exploit. Thus your eyes – at least for now – are still far more capable than the best DSLR relative to recognizing various tonal gradations. As I will demonstrate via my new model, “Doris” (shown below) of the Pittsburgh Zoo, even photos taken with high quality DSLRs sometimes need a bit of extra processing to match what your eyes can see. The photo below is the result of a processing technique I often employ to boost dynamic range when it is apparent that my camera’s sensor failed to capture what I remember seeing.
1) Good Dynamic Range Starts With A Good Camera
The first step in maximizing dynamic range is to have a camera that scores high in this category. DXO Mark can provide a good understanding of how DSLRs stack up against each other in this regard. The results from the D800 dynamic range testing have been amazing, clearly showing that it has the capacity to pull significant shadow detail while still keeping noise levels relatively low. If and when I actually get my hands on a D800, I will be able to determine this for myself! For this tutorial, I used my trusty Nikon D7000, which despite its modest price, has a very good dynamic range score.
But even with a D800 or other DSLR that excels in the dynamic range category, your photos are still likely going to need some additional processing to maximize their potential. For extreme lighting conditions, the only way to capture the full spectrum of exposures is with exposure bracketing and combining multiple images as done with high dynamic range software. In less dramatic lighting conditions, however, you may simply need to modify your exposure values using copies of a single image and combine them to create the optimal exposure for each part of your image. This need not be very cumbersome or time consuming, since with a bit of experimentation, you can quickly spot opportunities to enhance your photos’ dynamic range and make the necessary post processing modifications using Lightroom, Photoshop, and other software.
2) Variety Of Techniques
I chose to do most of my processing using Lightroom and Photoshop, my primary tools along with the full plug-in suite from NIK Software. I have no doubt that I could have used a variety of other photography processing software and techniques to achieve similar results.
3) Assessment Of Lighting Conditions
I knew this photo and lighting were going to cause an issue for my D7000, despite its respectable 13.9 DxO Mark dynamic range score. It was just shy of 1:00 PM on Sunday on Memorial Day weekend, and the sun was high and bright. I was taking a photo of my new model, Doris, who had ditched her fellow Pittsburgh Zoo gorillas and for some reason made her way over toward me in a little-visited portion of the park, where we were little more than 35 feet apart. She looked at me rather quizzically, decided I seemed harmless enough, sat down with her back up against a stone post, and proceeded to pose to me – or so I imagined…
Given the D7000’s tendency to overexpose a bit and the fact that Doris was a mixture of dark gray and black, I thought it wise to dial-in an exposure compensation of -.3. Even though I could see Doris’ beautiful brown eyes very clearly through my Nikon 70-200mm VR II and Nikon 1.4X teleconverter, I knew the camera’ sensor was not going to be able to accurately render the diverse tonal range, and that upon returning home, I was going to have some work to do in order to represent the dynamic range that my eyes saw. The picture below is the RAW file as it was brought into Lightroom 4.0 without any adjustments. As you can see, the D7000 did a respectable job, particularly with Doris’ silky fur coat, but her eyes are barely visible. And as with most RAW files, the image was pretty bland and boring.
4) Auto Adjustment In Lightroom 4
Based on my D7000’s characteristics and my understanding of the elements of a “good” photo, I created a number of Lightroom presets I apply to my photos that address exposure, contrast, shadows, color, contrast, highlights, sharpening, lens adjustments, etc. I almost always use a single preset that gets me 85-90% of what I expect a photo to be. The rest of my adjustments are made in Photoshop. After I applied a preset which I ingeniously named, “D7000 Preset”, which also included the use of Auto Tone, Lightroom 4 produced the image below. This preset improved the dark shadows associated with Doris’s pretty brown eyes and other body parts, but made her coat a bit too light. Admittedly, this is tricky image to get right with the Auto Tone adjustment feature. Lightroom 4’s “Shadows” control is a huge improvement over Lightroom 3’s “Fill Light” capability, as it has the ability to boost the exposure of the shadow regions without negatively impacting the rest of the photo. Fill Light often had the tendency to quickly “wash out” a photo and make it look as if a thin coat of gray paint had been dumped on it. Lightroom 4’s Shadows eliminates the unwanted color cast by only impacting those areas that are truly shadow areas, and represents a huge leap forward. Lightroom 4’s Auto Tone feature has also improved quite a bit over that of Lightroom 3. Lightroom 3’s Auto Tone button would almost always overexpose my photos, to the point where I stopped using it altogether. In contrast, Lightroom 4’s Auto Tone does a much better job, producing much more realistic mid-tones and blacks. But as good as both the Auto Tone and Shadows features are in Lightroom 4, you can see that Doris still needed some work. Her beautiful eyes simply weren’t showing their sparkle as of yet!
5) Boosting Exposure In Lightroom 4
The next experiment I performed was to boost the Exposure setting of a copy of this photo in Lightroom to see how much I could improve the shadow regions of Doris’ eyes beyond what the Shadow feature would allow. As you can see, my D7000 captured quite a bit more details and dynamic range than either the RAW or adjusted Lightroom 4 file suggested. And since I shot at ISO 100, I had a bit more latitude of “usable” dynamic range to play with, since RAW files shot at lower ISOs are not affected as much by noise as photos shot at higher ISOs. Had I taken this photo of Doris at 3200 ISO, I doubt that could have made the corresponding adjustments shown here without significantly boosting the noise levels of the shadows, and thus reducing the overall quality of the photo. So while the rest of the photos looked terribly overexposed, Doris’ eyes were clearly brighter and showing much more detail, color, and contrast than the other versions. Now you can begin to sense why the male gorillas of the Pittsburg Zoo melt under her gaze!
6) Combining The Exposures
As I mentioned, there are probably a variety of ways I could have achieved a similar result, but since I am very comfortable and familiar with Photoshop (I used version 6), I decided to bring in the original Lightroom photo into Photoshop, and then add the overexposed copy as a layer. Using layers, masks, and brush tool, I then combined the best of both photos, the results of which are much closer to what my eyes saw through the viewfinder. Not bad, but I thought Doris had a bit more potential.
7) Final Modifications
The last steps involved adjusting exposure, contrast noise reduction, sharpening, and color vibrance. In order to put more of the focus on Doris’ beautiful face and soulful eyes, I added a vignette using a Levels adjustment layer to darken the surrounding areas. Photo processing techniques, much like photos, are very subjective. The RAW file processing you see here produced something that is appealing and pleasant to my eyes. Your technique and preferences might take you down another path and result in an image that looks different than mine. Doris happened to like this picture so much, however, she made it her facebook profile photo. She tells me that she now receives dozens of messages each day from male gorillas around the globe, as well as female gorillas seeking to understand how they can achieve a similar look! :)
Maximizing the dynamic range in your photos starts with a DSLR that scores well in this category. And armed with some post-processing knowledge and experimentation, you can go a long way toward exploiting your photographs’ potential.