This is a brief excerpt from PhotoFocus
Pointing the camera up into the sun is an almost guarantee to get lens flares.You’ll see a washed out area with a geometric flare in the trees.
While the sun is generally incredibly useful to photographers, it can occasionally be annoying. If the sun hits your lens at an undesirable angle, you can end up with spots or flares that ruin a shot. Flares generally take on a geometric shape, and may be easy to miss while shooting. Additionally, a flare can significantly reduce the amount of contrast and saturation in your image.
The flare is typically caused by a very bright light sources (in most cases the sun). Flares are far more common in zoom lenses as they have multiple surfaces that are prone to light scatter. With a little practice you’ll learn to spot flares quickly. Getting rid of flares just requires a few strategies and modifications to your shooting style.
Once a lens is mounted to your camera, you should properly set the hood. With a quick turn (and perhaps a push of a release button) the hood can be removed. Reverse its direction and re-attach it to your lens in order to protect …
By: Richard Harrington