Love it or hate it, HDR photography is here to stay. HDR (High Dynamic Range) is a fairly new method of merging different exposures of the same photo in order to produce a new photo with consistent exposure throughout.
HDR can be used to expose shadows without blowing out skies or it can be used to create a painterly effect. This second use is what most people think of when they hear HDR, but this use is likely to be left behind while the subtle approach is more likely to stay.
The very first step in this process is to take bracketed pictures on your digital camera. A bracketed shot is one where you set the proper exposure, but then take an over-exposure and under-exposure without moving the camera. Many modern digital cameras already have this feature. Check your camera’s manual to find out how to bracket shots. If your camera doesn’t allow bracketing, you might be able to find a hack online that’s a passable workaround.
I use automatic bracketing to create three exposures for every photo. It’s possible to use more than three jpegs per HDR file, but my camera’s software limits it to three bracketed pictures at a time. I found that the closer to zero I set the exposure, the more realistic the final results were. One stop above and below proper exposure gives a noticeable HDR effect. Two stops above and below proper exposure create an almost cartoonish image.
Merging Different Exposures
The exciting thing about time lapse video is that it’s one of the few formats that lets you produce videos in HDR. Because of the specific requirements of HDR, such as lack of motion in the subject, it’s been mostly limited to still photos. These are easy enough to create using a newer version of Photoshop, but unwieldy when creating 1000+ images a week.
The predominant software solution is Photomatix Pro 3, which makes a stand-alone client dedicated to HDR that can also batch edit large numbers of files with limited user input. This is an excellent piece of software and well worth it for anyone who plans to do this on a regular basis. My only piece of advice, if you decide to buy, would be to look for links to the student discount program which will save you 60% to 75% off the $99 price. Photomatix offers a free trial version that is fully functional but imprints a watermark on all tone mapped photos. In my next HDR tutorial, I’ll describe the steps to batch process multiple files using Photomatix.
Composing a Video
After the HDR photos have been merged into jpeg files, you can create a video the same way you would with any other time lapse photo sequence. The only difference is that the exposures can vary more than normal and may require a deflicker filter. I’ll discuss this in the third HDR post.