The Special Group - November Drakensberg Workshop and a comment on Dynamic Range

I live a charmed life to be able to meet and work with the photography students that I have the privilege to meet on a monthly basis. This month’s Drakensberg workshop cemented this once more as we travelled through to Royal Natal with the largest group to date. Of course, group dynamics have a large part to play and the November group of photographers (the very same individuals as the Thanda group that I worked with two weeks ago) have hit it off from the word go. A disparate group is certainly a good description, geographically, personality wise and occupationally, but they have seemed to get on as if they have all known each other since kindergarten. I love groups like that. It turns my work into play…to the point that I start to feel guilty that I’m actually being paid to do what I do…although that happens a lot to be honest. 

Talking photography: sitting atop the Witches viewpoint makes you realize the importance of your camera’s histogram. Modern digital cameras are exceptionally good at resolving detail right from the darkest shadows through the brightest highlights. DXO Mark reports that a number of the top, and even a good number of the entry-level cameras available today, are able to resolve tonal detail in up to ten stops of light. I have a habit, a bad one I realize, of falling back on the safe number of seven stops of dynamic range in a digitial SLR as was the case with DSLRs some three generations back (think the Nikon D200, Canon 20D, maybe even the 30D). These cameras were excellent, but pulling details from the shadows still brought out the worst in the sensor. It still does, it just happens that the worst happens to be exceptionally good.

Getting shots like the image of the photographers on the Witches (above) then revolves around trusting the histogram. Forget about the image in the LCD screen. Chimping only makes sense if you are doing it effectively, and doing it effectively means using the full RGB histogram. In the case of this image the histogram was spread right across the range from the very darkest shadow, where is wasn’t clipping, through to the brightest highlight, where it very definitely was clipping (the sun will pretty much always clip, and if it doesn’t it means you have an extremely underexposed shot that is rendering everything except the sun in pitch black). Yes, a tonal blend would be a great way to get maximum dynamic range right from the very darkest shadows through the highlights around the sun. Sometimes we don’t have time to do this though. Sometimes a quick single frame is all that we can, or want, to do. Trust the histogram. Processing the image in Capture NX2 (Photoshop would have been as easy), I brightened the darks and shadows portion of the image while masking off the bright sky. The same thing was then done in reverse by darkening the sky portion and masking off the now not so shadowy foreground. There are still the same number of stops of light that have been recorded by the camera, but the image has a greater perceived dynamic range. The miraculous thing is that when zooming in to 100% in the shadows, there is little to no noise (and what small noise there is can easily be cleaned up). The trick here is to shoot at the base ISO of the camera. Anything higher and the noise in the shadows in amplified in the analogue to digital conversion within the camera. Neat that cameras have gotten so good! We just need to learn how to effectively use them. 

Another wonderful weekend in the Berg. Sitting at Witsieshoek after 3 days where the weather gods smiled and gave us perfection, a sense of supreme satisfaction creeps in. Now it’s back to the studio, clients, processing, keywording (aaargh) and marketing. There are downsides to being a freelance photographer and instructor, but the good outweighs the bad a hundred to one!