Some of you may have heard of the term, but if you’re not into photography there’s a good chance you don’t know exactly what high dynamic range (HDR) photos are. Simply put, the goal of the HDR technique is to expand the dynamic range (difference between the light and dark areas) of the image so that it’s closer to what the human eye sees. Camera sensors, although constantly being improved upon, still can’t match the range between detail in light and dark areas as well as your eyeballs. If a scene has something in direct sunlight and something else in deep shadow, you’re going to lose detail in one or both areas when you rely on just one exposure.

To solve that problem, the premise of HDR is simple: take several exposures of the same scene, one for the darkest areas, one for the lightest areas, and one or more in between, and then combine them in post-processing so that all areas of the final image have detail and are not blocked out (shadows) or blown out (highlights).

The image at the top of this post is an HDR comprised of three separate exposures (see below). The wine was in shadow, sitting on my balcony railing (which faces east, and this was sunset), while the background (a treeline) was in bright sunlight. There was no way the camera sensor could capture the color and detail in the wine glass and the nice bright green of the trees. So the solution was combining these three exposures. There are a number of ways to do this; I personally love Photomatix by HDR Soft (standalone $99, also available in various plugin flavors). I’m not going to dive into the details on how to use that particular tool, but basically you load up the relevant exposures in Photomatix, and then play with the sliders until you achieve the desired result.

While Photomatix does offer to align the source images when you first load them, it’s obviously best to shoot the scene with your camera on a tripod — actual stability from frame to frame is no substitute for software tricks. Most DSLR’s have a feature called bracketing which makes firing off multiple exposures of varying compensation easy; on my D90, I turn on bracketing and then with one press of the shutter release it will fire off all the exposures to fill that bracket in less than a second, automatically adjusting the exposure compensation in between each frame. If your camera doesn’t have bracketing, you can of course adjust exposure compensation manually and then fire each shot — it will just take a little longer.

What I’ve shown here — and really the only type of HDR I’ve ever personally done — is a subtle style whose purpose is to closely mimic reality, and do so in a way that only a trained eye would even suspect it might be an HDR. At the other end of the spectrum are the wildly rich HDRs (such as this one), which are a style in their own respect but certainly not representative of reality. Some criticize these more intense HDRs as “cartoony” and there’s a definite divide in the photographic community among those who hate the style and those that appreciate it. There are, of course, also plenty of people — myself included — who say “Art is art” and, you know, do whatever makes you happy.

As I said, there are a number of methods out there to combine photos into an HDR image. It is possible to do it in newer versions of Photoshop too, if you have that…which I do, but I prefer Photomatix because it’s so easy to manipulate the various properties relevant to an HDR image. If you’ve got scenes with huge dynamic ranges, try it out!

Want to see more HDR photos?

• 35 Fantastic HDR photos (Smashing Magazine)
• HDR group pool on Flickr
• Quality HDR group pool on Flickr