Blog: Musings on the Future with High Dynamic Range (HDR) Photography

by Andy Shafer

Photographer: Fanny Schertzer

Standard (Before) HDR (After)

The human sense of sight can appreciate an expanded visual spectrum. High Dynamic Range (HDR) images are photography’s answer to an expanded visual world.

All the luminance values in a real-world scene are represented proportionately and stored in an HDR image. Adjusting the exposure of an HDR image is like adjusting the exposure of a photograph during a shoot in the real world. The capability allows one to create blurs and lighting effects that look realistic.

So what’s the future look like using HDR? Is this technique going to invigorate the demand for magazines, books, or the iPad? Does HDR negate the depth of field?

Should we wait to buy conventional digital cameras or wait until the HDR model is introduced to the market place? The future with HDR is akin to developing images on glass plates, as opposed to using silver-based negative film. HDR is the next wave that once has run its course will change the photographic industry, as we know it today.

The WOW is now.

The reaction of first time viewers of HDR photos is often, WOW! Interest level of HDR can be measured by the quality of the WOW factor. Once you’ve hit that level, there is no turning back. It is the future.

In image processing, computer graphics, and photography, high dynamic range imaging is a set of techniques that allow a greater spectrum of luminance between the lightest and darkest areas of an image, than standard photographic techniques. This wider dynamic range allows HDR images to more accurately represent the wide range of intensity levels found in real scenes, ranging from direct sunlight to faint starlight.

Two Main Sources

The two main sources of HDR imagery are computer renderings and merging of multiple photographs. Those in turn are known as low dynamic range, also called standard dynamic range photographs.

Tone mapping techniques, which reduce overall contrast to facilitate display of HDR images on devices with lower dynamic range, can be applied to produce images with preserved or exaggerated local contrast for artistic effect.

The dynamic range of sensors used in digital photography is many times less than that of the human eye and generally not as wide as that of chemical photographic media. In the domain of digital imaging, algorithms have been developed to map the image differently in shadow and in highlight in order to better distribute the lighting range across the image.

These techniques are known as high dynamic range imaging, and usually involves overcoming the limited dynamic range of the sensor array by selectively combining multiple exposures of the same scene in order to retain detail in light and dark areas. The same approach has been used in chemical photography to capture an extremely-wide dynamic range: A three-layer film with each underlying layer at 1/100 the sensitivity of the next higher one has been used to record nuclear-weapons tests.

HDR limitation is with output

The most severe dynamic-range limitation in photography is reproduction on paper or computer screens. In that case, dynamic range adjustment can be effective in revealing detail throughout light and dark areas: The principle is the same as that of dodging and burning (using different lengths of exposures in different areas when making a photographic print) in the darkroom.

We’re in for the long haul with HDR imaging. The more it’s used in production, the more development dollars will flow into new technological ideas. We are accepting High Definition images as a standard, which is a segue for viewing High Dynamic Range as the new standard in imaging.