Practically every day, one can see threads on photographic forums where members discuss the various different modes of automatic exposure, trying to find the right one. As a rule, these discussions result in the same question – what compensation to automatic metering ought one set to get consistently good exposure? It turns out that no autoexposure mode universally guarantees good out-of-box results.
Suppose you have read somewhere that the dynamic range of your camera at a certain ISO setting is 11 stops. And here comes the immediate question – how can one use such a treasure to its full potential? Optimal exposure for RAW is the answer. But now we need to explain what we mean when we say, “optimal exposure for RAW”. Let’s start with one of the problems, which arises as a result of non-optimal exposure for RAW. Here is a typical wide dynamic range low-light scene. According to Sekonic spot-meter, it is wider than 11 stops:
One of the tests that we will be including in our upcoming Nikon D810 review is a dynamic range comparison between the D810 and the D800E. Instead of making our readers wait for this comparison, we decided to publish it in a separate article. Whether one shoots landscapes or portraits, dynamic range is important, because it allows recovering of both shadow and highlight details in RAW images. With the release of the Nikon D810, one might wonder if it is any better than the D800 / D800E cameras in dynamic range performance. Since the D810 has a base ISO of 64, we decided to provide ISO 64 and ISO 100 samples to see if there is any discernible difference between the two. We also provided ISO 3200 samples to show differences in dynamic range at high ISOs between these cameras.
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.