Everyone enjoys sunset or sunrise photography. Who, with a camera, has not tried to get that "special image" with the sun going down over a lake or mountain peak.  What happened, we ask, when we look at our image later and find that either the bright sky was burned out or the foreground was so dark that it could not be seen.  It was several years of these attempts before I was standing next to a photographer in a "First Light in the Smokies" photo class and asked what filter he was using. Of course the answer was a "Graduated Density" filter.  This filter, similar to, a polarizing filter, has the effect of reducing the glare of the bright sky or the sun while allowing the darker part of the image to be shot with clear glass.  The results are incredible.  Of course, you can now simulate this affect in Photoshop but it is never as good as doing it right in the field (as in most photographic experiences).  Also, while you are out there shooting with your Grad. Density Filter bracket your shots so that you later can either blend these images in photoshop or an HDR plug-in or simply pick the ones you like best. 

Larry Wilkinson