HDR 101
As I was heading home this evening, I noticed that the sky was getting some nice colour. I pulled into Nose Hill Park just off 64th, set up my tripod and camera (yes, I did just happen to have it with me).
Sunsets are notoriously hard to meter, but we do get a little leeway using digital. The original, manual, way was to bracket your shot, so that you were sure that you would get at least one that was the correct exposure. Now that same old trick is the cornerstone for the new digital hotness.
High Dynamic Range is a trick that was developed to help deal with the fact that digital cameras can't encapsulate as much of a dynamic range than film. The result is much more detail in your blacks and whites, and some amazing colours.
First you need to get some bracketed shots. Most cameras do this automagically, but if you can't figure it out, you just need to use the manual mode to create a set of shots where one is overexposed, one what you believe to be right, and one overexposed. Be sure to use a tripod, or it's all for naught.
Next, you need to load up Photoshop. Select Tools->Automate->Merge to HDR... Browse for your photos and be sure to check off the automatic align source images. Here you can set the colourdepth per channel. I usually run with 16, because my poor PC hates 32, and 8 bit doesn't really gain you much. Now move the slider until you have a good contrast within your shot, then continue. Next you will get to set your exposure and gamma. I usually play them against each other to get the details where I want them in the photo. If you turn your exposure up, you can pull your gamma down in order to maintain the overall greyness of your photo. Vice versa if you want to bring up the details in your blacks and not blow out the whole picture.
You will now have a beautiful image to continue with your normal Photoshopping.
