In several of my blog articles, I encourage the spreading-out of tonal ranges in order to portray a certain richness that comes from using the entire tonal scale.  In this article, I present a case where it is desirable to use only the upper half of the tonal scale.

 

Images such as this may be termed “high key”, indicating that the lighter values are dominant (as opposed to “low key” where the darker values are dominant, or “balanced” where neither the lighter nor the darker values are dominant).  Cameras with automatic exposure capabilities are programmed to produce “balanced” photographs.  Achieving an “high key” photograph can be accomplished in the camera by intentionally over-exposing the image (usually there is an exposure compensation control which affords increasing (or decreasing) the exposure in either one-half or one-third F-stop increments).  The danger to such in-camera exposure adjustment is that you run the risk of blowing out the highlights (where higher values get merged together into a single white, thus losing detail).  More often, especially when shooting in RAW format, it is safer to expose for a tonally balanced image and then manipulate the tonal ranges on the computer; this way, you’ll have more data to work with and more precise control over how much tonal shift to apply.

 

The above image is a crop (roughly 40% by area) from a larger image containing regions of evergreens which were significantly darker.  The histogram for the original (uncropped) image was much more “balanced” in terms of lighter and darker values, and yet the original image was distracted with respect to subject matter.  When I captured the image, I was drawn to these rugged mountain peaks enshrouded by clouds an snow — it looked bitter cold — a curious and unexpected scene in the middle of an otherwise hot and relatively level desert terrain.  As can be seen by the histogram superimposed above, the cropped image is almost exclusively using values in the upper half of the tonal scale.  Quite easily I could have spread these values out — producing a more balanced histogram — but that would have told a different story from the one I “heard” while capturing the photograph.

 

This image was exposed for 1/125s at f/11, using a 100 mm f2.8 macro lens on a Canon EOS 5D.