I have to confess. I'm a fall leaf color addict. If the leaves have changed to their fall colors, I'm struggling to resist being outdoors 100% of the daylight hours with a camera in my hands. Fortunately, I don't have to go far from home to find some of the best color available anywhere.
Even with colorful trees being easy to find, photographing the fall color can be very challenging and one of those challenges is to create a compelling composition. Many of the most-brilliantly colored local trees, primarily old maples, are found in town, where houses and other buildings, power lines, signs, etc. interfere with the natural look I'm typically seeking. A picture of a complete tree may capture the color, but the likelihood of something undesirable being in the frame is quite high. Even in the countryside, the ideal trees can be difficult to work into great compositions for a variety of reasons including a lack of supporting elements.
One fall foliage technique I like to use is isolation of the colorful leaves of one tree with other parts of the same tree or another tree filling the rest of the frame. Find an attractive leaf or set of leaves that are in good condition and then determine what could be a good background for the composition.
Determine the focal length of your lens based on how large the foreground leaves should be in relation to the selected background. The focal length decision will also be affected by how large the selected background is and the space you have to work in with a longer focal length requiring less background area needed. The longer the focal length selected, the easier it will be to make the background blurred and of course, the vice versa is also true.
Determine the aperture used based on how much depth of field is desired with a very wide aperture capable of putting the background into a primary-subject-isolating blur. Also note that a wider aperture makes a faster shutter speed easier to obtain (at a lower ISO setting) and a faster shutter speed may be necessary to stop any wind-imparted motion of the primary subject leaf or leaves.
Don't stop with your first setup. Continue to refine the shot until you have it perfected. Then find another composition to work on.
The brilliantly colored maple tree in this picture was on the corner of an in-town street intersection with power lines and houses directly behind it. I moved in close to the foreground leaves and aligned the angle of view with the lines created by the trunks and limbs. The backlit leaves on the other side of the tree and some green grass across the street complete the composition. The result is a brilliantly colored fall photo that is, at least somewhat, unique.
While photo trips to grand landscapes with brilliantly colored trees are awesome, knowing the isolation technique can land great fall foliage images much closer to home (for many of us) and in many more locations (for all of us).