Taming HDR . . . moving towards Extended Dynamic Range Imaging
By Rick Hulbert
High Dynamic Range Imaging, or HDR, has become one of the more controversial subjects in photography today. Advocates of the processing technique are often so eager to take advantage of the “promise” that HDR can provide, that they tend to go overboard in their desire to maximize the various effects. This has led some people referring to HDR as “Highly Distorted Reality,” a reference that has been earned by those that use the medium to create what some call “surrealist art.”
Those of us that are interested in “documenting reality” can benefit hugely from the whole genre of High, or what I prefer to call Extended Dynamic Range Imaging. The human eye/brain combination has the unique ability to “see” a vast dynamic range of light seemingly all at once… whereas film, digital sensors, matte and glossy prints, computer monitors, and digital projectors are quite limited in this regard. What we think we see as humans is an illusion, something we discuss in the workshops I lead. The fact is that while photography is also an illusion, we can more closely approximate what we perceive as humans by extending the dynamic range of light perceived in a photograph.
What has made HDR so popular is the advent of ever-improving software that allows everyone to play with the effects of maximizing the dynamic range of photographs in a way that can be easily viewed. The problem is that the “effects” are so easy to achieve, there is a natural tendency to overdo those effects in postprocessing. This “over the top” exuberance has given HDR a negative reference in some circles. While beginning photographers tend to be in awe of the effects, more experienced enthusiasts and professional photographers tend to turn up their noses.
Think of how we view flash photography…
If you can tell that a flash or strobe or speed light was obviously used, it probably means that you overdid it. The same principle is true for HDR imaging. If you can tell that HDR tone mapping was employed, it might just be that you overdid it. Having said that, there are times when aggressive HDR is just right. Old buildings and machinery along with high-tech industrial objects can be just the ticket for aggressive HDR.
One of the secrets of moving towards a kinder, gentler, more reality-based approach to increasing the dynamic range in images is to appreciate the influence of “contrast.” While we have been increasing our collective sophistication of image making by working with “clarity,” “vibrance,” and “luminance,” the key ingredient in taming HDR is learning to control, manage, and harness “contrast.”
The future of HDR imaging is great in my opinion.
I believe that once manufacturers of digital sensors can find a way to quantify and label “dynamic range” so that consumers can understand it, the “megapixel race” will start to subside and the “dynamic range race” will take off.
The above topics and more are covered in my Hands On HDR Workshop given at the Vancouver Photo Workshop Studios.