Stunning silhouette photography with any camera.
Whether you have a compact or digital SLR camera, shooting great silhouettes is easy with the auto exposure lock trick.
First, remember that for a great silhouette photograph, it's important to have an interesting foreground (silhouette) and background. If one of these is boring the image will fall flat.
For most silhouette images, the background will probably be the sky. The most interesting skies are those that are neither completely cloudy, nor completely clear. You need some interest in the sky - a few clouds in the sky is great, as is the sky around dawn and dusk. The vibrant hues of this time of day will really help your image too.
Try composing your photograph so that the sun is coming from behind the silhouetted subject. If the sun is directly behind the subject, make sure the sun is hidden by your subject so you don't get lens flare.
To get the correct exposure you'll need to have your camera take a reading from the sky - or whatever background you're using - rather than your silhouetted subject. This will keep the detail out of your subject, rendering it as a perfect silhouette.
First, make sure the flash is turned off in case the camera tries to compensate for the dark of the silhouette.
Then, once you've framed your composition, move the camera slightly so the focus point (usually the centre of the viewfinder or preview screen) is aimed at your background. Depress the shutter halfway and hold it there while moving the camera back to the original position.
Now squeeze the shutter the rest of the way to take your image. As always, it's worth taking a couple of extra shots as your camera may record slightly different exposures and it's good to have a choice.
This technique will work all cameras that have auto exposure lock (AE-Lock) set to run on the half press of the shutter. If this trick doesn't work with your camera, check the manual for how to set the AE-Lock. With some digital SLRs, for example, auto exposure lock on a half press isn't the default setting.
Safety tip: Don't look at the sun for long periods through the camera lens. If you're using a telephoto lens don't look at it at all.
http://photography.caiminjones.com/2006/08/stunning_silhouette_photograph.php 
