Local Contrast Enhancement Adds Snap to Photos
Sometimes one comes across an image that has a full range of tones and good contrast, but somehow still lacks the punch to make it a satisfying visual experience. Narrowly examining the photo, we might notice that one of the major compositional elements seems a little dull. Accustomed as we are to paying a great deal of attention to an image's overall tonal range and contrast, we may forget that global adjustments of these parameters are not always sufficent to bring forth the full potential of the photograph. Some additional localized tweaking may be just the ticket for bringing the photo to life.
The photo above, Orchard in Full Flower, has good overall contrast, but the barn looks rather flat. I drove by this scene near Leavenworth, Washington, earlier in the day, and determined to return in late afternoon when the sun would be lower and the lighting more attractive, and the north-facing barn illuminated obliquely. When I did return, the sun had not yet swung far enough north to strike the face of the barn to bring out its texture. At the same time, however, the sun was close to sinking behind a distant hill, at which point the entire scene would be in shade, and the late afternoon ambiance lost. So I made the photograph anyway, under the lighting conditions I had to work with. Sure enough, the barn, although the focal point of the photo, looks dull and uninteresting.
In order to impart some snap to the barn, I first made a somewhat rough selection of the barn face in my image editing program. Then as shown in the screen shot above, I used the curves dialog box to make a modest contrast adjustment (the light grey mountain behind the curve is the barn's histogram). This rather improved matters, but I still wasn't satisfied, so I repeated the same curves adjustment twice more, at which point I obtained the increased level of contrast I was looking for. Not quite the same thing as grazing illumination by the sun, but a big improvement to the success of the image, as seen below.
