Tech Myths: Boosting Reality

HDR: Photographic Magic

Myth: Creating hyper-real HDR photographic images can be accomplished for little to no money. True or false?

Once upon a time, I considered myself an amateur photographer. It was a hobby that started in high school and persisted to today, even though I no longer have time to pursue it avidly. Like most people, I’ve visited amazing locations and captured a handful of photographs that rise far above the average—the stuff you want to put on your wall. Often, I’d take multiple exposures of such scenes with a process called bracketing. You identify what the camera says is the optimal exposure for a scene, capture it, then take additional exposures above and below that optimum.

Sometimes, these other exposures will capture details that were missed at the supposedly optimal setting. If what you really want to see is the detail in the shadows, you’ll prefer an overexposed image, even though it will likely mean losing detail in the bright areas, such as the sky. This is because both film and digital image sensors have a lower dynamic range than the human eye. They simply can’t capture the entire range of luminous detail we normally observe. (Real-world scenes can have dynamic ranges of over 50,000:1, while the media we use to try and represent these scenes is limited to about 300:1. It’s a bit like MP3s in the audio world. You lose some fidelity while trying to reach an optimal compromise. MP3s never sound as good as the original CD, which in turn never sounds as good as the original studio recording.

I had a photography instructor in college who told the class that while you could spend thousands of dollars on photo gear, the real art happened in the photographer’s mind. He noted how one of the best pictures he’d ever taken had been a close-up of a flower taken with a disposable film camera and a magnifying lens. In his imagination’s eye, he’d seen the potential of the situation given the tools he had on hand, and magic had followed.

Another past instructor of mine (the one with whom I did most of my comparative religious studies) once noted that magic is nothing more than the alteration of perception—and thus of reality. With that flower photo, magic had happened both in the photographer’s mind as well as the viewer’s. We all know that flowers don’t look like that, but just adding a magnifying glass altered reality and gave that real object a whole new spin. So often, such transformations now happen in photo editing software or are wholly created from scratch as computer graphics. Maybe I’m old-fashioned. I don’t want my artistic reality invented—just boosted a bit.

Consider the three images shown at the top of this page. These are crops from the original photos I took for my Myths segment on caffeine several weeks ago. As you can see, the first exposure is too dark, but beyond the crop’s borders I got some great details of the clouds (not shown here), which made a kind of cool aura around me. The middle exposure gives the best detail of the fluid level inside the container. The final exposure, done with a flash, gives the best detail of the foreground, but all sky detail was lost and, quite honestly, there was way more detail of me and the inside of my nose than I’m sure anyone wanted to see. In the end, I took the label from the flash exposure and Photoshopped it onto the exposure with the cloud detail—an imperfect, time-intensive solution that still left me unsatisfied. But so far as I knew, there was no better recourse within my means.