Since the Fall Color Field Trip is upon us I'll attempt to pass on some information to help you get the most benefit from the experience, whether you get to make the trip or not.
The Owens Valley, especially the Bishop area, is probably one of the most picturesque fall color areas in California due to it's topography. It has both the deepest valley, and the highest mountain in the state. This provides the climatic conditions necessary for a long fall color season. The leaves change color due to the drop in temperature and the decrease in daylight hours. September 22 is the halfway point between the longest day (June 22nd) and the shortest day (December 22nd) of the year, and the time of year when the daily temperatures begin to fall. So, when the surface temperature at 4,000 feet (the elevation at Bishop) falls to 49 degrees freezing occurs at 9,000 feet – Lake Sabrina's elevation – and the leaves get the message! We can watch the colors come alive at the 13,000 foot level and progress down the mountains to the lakeshore, the banks of the streams, and finally to the valley floor The leaves on different species of trees, Aspen, Birch, and Cottonwood turn different colors, accounting for the bright yellow, orange and red hues we love to photograph. Adding to that are the colors of various plants, some red, some yellow going through the same cycle.
Look into the shadows for reflections that can add a great deal of interest to the picture of a stream or lake with Aspens or Birch along the banks. Long exposures produce silky water flowing over riffles, but may require adding a polarizer when you wouldn't ordinarily use one, just to get a long enough exposure. A tripod and remote shutter release is generally required for best results in scenics and nature photography, because to get great depth of field you need to be shooting at small apertures like f-16 or f-22, which requires you (or the camera) to compensate with slow shutter speeds. Out of focus backgrounds invariably result in “snapshots”. Wide angle lenses provide the most depth of field for a given aperture, however, telephoto lenses effect perspective by pulling distant mountains or objects closer. Knowing how to use your various lenses to best advantage is a good skill to have in nature photography.
Lighting conditions are very important in getting pleasing colors in fall pictures. I've learned that, by evaluating pictures taken at Lake Sabrina in the morning compared to pictures taken in the afternoon. Front lighted trees in the morning at Lake Sabrina have a bright, gleaming, saturated yellow color, whereas the same stand of trees from the same vantage point, back-lit in the afternoon, seem lifeless, contrasty, and dull. The lesson to be learned is remember to shoot sunlit fall foliage “down sun”. Another case of “look for the picture behind you, too”.
One of the things that make fall color pictures a lasting visual experience are the effects from complimentary colors. Blue is the complement of orange, and when those are found together in nature are very pleasing to the eye. (Sunsets, for example). Coincidentally, at higher elevations the air is clear of haze, and as you look up from the horizon you may notice that the sky becomes a very dark blue. (In fact, using a polarizer at elevations 5,000 feet or more above the surface may result in an undesirably dark sky). A picture of white puffy clouds in a bright blue sky, with a foundation of yellow and orange foliage supported by forest browns, greys, and greens form a natural setting, and a thoughtfully balanced composition produces a three dimensional image in the viewers mind, while looking at a two dimensional ( a flat surface) picture.. Producing an arrangement of elements that takes advantage of these eye and brain interactions produces images with stunning impact.
If you haven't recognized this important fact before now, let me emphasize it once more. The first thing an experienced Judge looks for is IMPACT. After that there is a contest for second and third place.