Monday, June 22, 2009
The Cliffs Above the Austin 360 Bridge
A lot of people don't know it but on the north side of the Austin 360 bridge there is a trail that is fairly accessible that goes to the top of the cliffs overlooking the bridge. It's a beautiful place for portraits especially at sunset. I shot this about 45 minutes before sunset. I wasn't planning this shot. I was looking for a place to set up my tripod and looked back at my girlfriend looking out over the cliff. The light was perfect. So on the fly I shot a single RAW capture and then used a program called Essential HDR to generate a HDR picture from the single exposure.
Yes, you can generate a HDR image from a single exposure. It helps a lot if the exposure is in RAW format, as RAW files have several exposures worth of information to work with. Some cameras are better than others for this as not all sensors are created equal. One of the best cameras to use when taking this approach is the Nikon D700. It has a good 5 or 6 EV's of information in the RAW files. That gives you a lot to work with from a single capture.
As far as how you create a HDR image from a single RAW file, its pretty simple. You just use your RAW editor to create 3 or more separate jpegs at different exposure settings, then use your HDR editor to combine them into the HDR file. Essential HDR is really convenient for this - it will do all the heavy lifting of generating a HDR from a single capture for you, you just tell it to generate a HDR from a RAW file, point to the file, and then a couple seconds later it gives you the HDR image. The advantage to using this method is that you can capture moving subjects sharply - notice the waves in the water below are sharp. The disadvantage is that it can't cover the range of actually taking multiple exposures - you're limited to what the RAW file can capture. 5 or 6 EV's is ok, but I've run into lots of situations where I had to balance up to 15 EV's, so a single RAW capture wouldn't cut it there.
Side note, one thing I like about Essential HDR is that it is very good about not introducing a lot of unwanted HDR artifacts. I also processed this shot through Photomatix and got some pretty bad halos around the tree. I tend to use different HDR editors for different things. I like Photomatix very much for my car stuff (its kind of slow and clumsy to use though). Essential HDR I use for architectural, people/portrait, and pretty much anything where I need a more natural look.