Friday, May 11, 2012
Jeff Stevensen: HDR - The Web’s Loudness War?
[Abandoned Tinsel Factory, Windsor Locks, Connecticut]
Surely you’ve seen HDR photographs by now. HDR is an acronym for High Dynamic Range imaging. It’s a post-production technique in which one combines several different exposures of a subject into one final photo; the final photo has more detail in extreme highlights and extreme shadows than a conventional, single exposure can capture.
HDR can be a lot of fun and initially exciting. Unfortunately, the most common “look” people are using with HDR is somewhere between surreal and cartoonish. Colors are screamingly over-saturated; dark “contrast clouds” surround areas of smooth tone. Textural detail is exaggerated to the point of being “crunchy.” The overall effect is a kind of LSD eye candy.
[Railroad Bridge, Enfield, an example of HDR artifacting.]
Exciting At First
When I first saw HDR photos I was fascinated and entranced. I had to know right away how this strange effect was created. I acquired the special software, read up on the technique and began experimenting. I hadn’t been this hypnotized since I had discovered color infrared film in college.
One month into my HDR crush I had an appointment with an art director of experience and distinction. No, I didn’t bring any HDR prints with me. We got onto discussing trends in digital photography and as I was about to bring up my excitement about HDR he blurted out how he was “sick and tired of all that HDR crap.” I recovered nicely, and didn’t let on that I had started using it. I was a bit perplexed by his attitude; wasn’t this new and exciting?
“New” is relative. He’d already seen his fill.
[Coast Guard Fog Horn Station at Dyer Cove, Cape Elizabeth, Maine]
My Excitement Dims
Within a relatively short time I could see his point of view. My flame of infatuation had dimmed, and I was chafing at the artificial boundaries HDR was drawing around the implied space of my vision. In short, it seemed more and more to me to be simply a gimmick.
There are people doing HDR well, and I enjoy looking at their work. Take a look at Ken Kaminesky or Trey Ratcliff or Captain Kimeo. For me, a little goes a long way, like cotton candy. I just can’t push HDR as hard as they do.
After my HDR crush began fading, I had occasion to shoot some commercial interiors that were “fast and loose.” The budget allowed only minimal supplemental lighting. Since I was shooting these interiors on a tripod with bracketed exposures, I decided to process an HDR variant of my image strictly for contrast control in key highlight areas. I then layered the HDR version with a “normal” version and combined them into a final image that looked extended and clean, without the artificial tell-tales of HDR. The results excited me again. HDR suddenly became a tool to extend my imaging, not as an end in itself.
A New Tool
I now use HDR “in the background” with confidence on personal landscape work and a fair amount of architectural jobs holding window detail. It’s a powerful tool to add to all my others, both lighting on-set and in post processing. High dynamic range capture can extend the tonal response of the camera to more reflect the extreme contrast range of the human eye — or even to exceed it.
[Strawberry Fields, Cape Elizabeth, Maine, combining "straight" processing with an HDR layer subtly combined for foreground texture enhancement. You still need great light.]
[Twilight, Kettle Cove, Cape Elizabeth, Maine, combining "straight" processing with an HDR layer for subtle foreground texture enhancement.]
Don’t Use The Defaults!
What is tone-mapping? HDR utilizes high bit-depth color spaces, typically 32 bit, for billions of steps of tonal separation. Having captured this high bit tonal information, you must figure out how to get it into a form you can actually see and use on your computer. Because there are no high-bit monitors on the market, 256 values of separation are the most you will be able to see on the monitor. (A print may have a contrast range of only 50:1.)
Your choices are to compress the extended HDR range, like squeezing a sponge and jamming it into a shot glass; or to choose selectively from throughout the vast range of information, weighting your choices for either highlight detail, shadow detail, or some compromise. This is where the specialized software, such as Photomatix or Photoshop, enter the picture. You use this specialized software to merge (map) the tonal information together into (ultimately) an 8-bit visual range.
It has been reliably and consistently established through scientific and medical research that the range of human visual response for the cones in our eyes (color vision) is just about 100:1. We have marvelous sensitivity to move this range of response across huge levels of illumination, but for a given illumination level our contrast range is 100:1 for color sensitivity.
Straight-line compression into human visual response range makes for low contrast, flat images. So the software employs sophisticated algorithms and user-directed sliders to add enhancements to different parts of the picture. These enhancements go far beyond simply merging the data. Fine detail enhancement makes the picture “crunchy.” Dark “contrast clouds” surround broad areas of tone, such as sky and clouds, giving a brooding look. And saturation can go through the roof. This creates the most common HDR default “look,” a tonal mash both compacted and exaggerated, with sizzling, LSD-like colors.
[Spurwink Marsh, Scarborough, Maine, with heavy HDR processing artifacts.]
In the 1960’s, record companies began over-driving the levels at which they cut 45 RPM records. These overdriven levels trashed the high frequency response for people with good equipment, but most people were listening to their records with cheap home record players, or on jukeboxes. The overdriven sound made the record sound “louder,” and people responded by buying more of those records. Soon, all the record companies began to overdrive their 45 RPM records to be “louder.” And they did their best to “out-loud” their competitors. The harsh sound became the standard, even though it was of lower quality.
In pop music today, the loudness wars have taken sophisticated form, due to the use of software tools which were unavailable to recording engineers back in the 1960s. Dynamic range is compressed in the mix and or mastering stage (or both), jamming the music signal up toward the maximum digital sound level (0 dBFS – decibels relative to full scale). Sometimes it will be pushed past 0 dBFS, totally flattening the once rounded peaks of the audio waveform, producing gross digital distortion. Then the sound goes through another stage of data compression to reduce the file size into an mp3 for your ipod, etc. This “lossy” type of compression discards or reduces further the fine details and shadings of the music. Young people now actually prefer this lower quality/lower dynamic range than that of a CD or LP; it’s the new music norm. (Thank you Bill Pauluh for clarifying the technical description in this paragraph.)
The Web Is In A Loudness War
The web today is engaged in a visual “loudness war.” You’ve the barest fraction of a second to catch a page surfer’s interest and keep him from clicking away. More contrast! Pump up the color! Grunge it! Make the detail pop! Hold that viewer a fraction of a second longer.
I don’t think a processing technique should call attention to itself as the end product of a photograph, and that’s what most HDR or other effects-driven photos are about. Neither HDR nor any other filter can make an inherently boring picture into an interesting one. It can, however, make an inherently boring photograph into one marginally intriguing for a half-second or so — until, like my art director friend, you’ve simply had enough. Then you tune it out with the other hype.
If HDR’s pedal-to-the-metal look is a kind of digital photography futurism, apps like Instagram or Hipstamatic (“digital photography never looked so analog”) are its retro-rendering alternative. Amanda Petrucich has a post on Buzzfeed in which she describes these trends as “manufactured nostalgia” and “pining for old-timey, nuts-and-bolts craftsmanship, even if they’ve never experienced it firsthand and aren’t prepared for all the work it takes to actually achieve.” The second part is certainly true. Good art is hard work, and most people who actually had to work within the frustrating confines of 1960′s color photography most certainly do not miss it. “Effects” are people’s tacit acknowledgement of the absence of a compelling personal vision. See my post on film and digital vision.
Take heart that all this casting about for something to make your photographs “better” is just one stage in a long personal journey. One day in my junior year at Syracuse University (BS Photojournalism, 1974), I was mounting a color photograph to an art board for display. One of the grad students sauntered over, studied it for a moment and summed it up. “A reticulated, infrared fisheye shot. Man, that’s got every gimmick in the book.”
Remember that 99.99% of the great photographs of all time were taken without use of HDR or other effects processing. But will the HDR “loudness” become the new visual norm?
Recommended reading: The Artists Eyes, Vision And The History Of Art, by Michael F. Marmor and James G Ravin, Abrams, New York 2009. The authors, ophthamologists, cover in great detail the nature of human vision and how art over the centuries has been created through the medium of biological vision.