Hdr pages from 42 1 f08 cjet 2

HDR photo by

Paul Davidson Edinburgh, UK paul.davidson7@virgin.net flickr.com/elementalpaul/

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Fall 2008

From photographer Paul Davidson Of all my HDR images this is one of my favorites. Taken on a trip to the Canadian Rockies in May 2008, there’s a lot to engage the eye: the color of the boats, the reflections of the clouds, mountains and trees. I particularly like the clearness of the water in the foreground. Looking at this image you wouldn’t know there’s a large hotel and leisure complex behind me!

Because an HDR is made of multiple exposures, I ­recommend using a tripod to ensure the images align. I don’t like carrying a tripod so most of my images, including this one, are done freehand. The Pentax K10D camera I use has built in image stabilization but you still need a steady hand to make sure there’s no misalignment. The image was processed using Photomatix Pro and iPhoto.

Fall 2008

Communication: Journalism Education Today • 41

Technobabble Definition High Dynamic Range Imaging allows a greater dynamic range of exposures than normal digital imaging techniques.

HDRI attempts to represent more accurately the wide range of intensity levels found in real scenes ranging from shadows to direct sunlight.

History • Charles Wyckoff originally developed High Dynamic Range Imaging in the 1930s and 1940s for detailed pictures of nuclear explosions that appeared on the cover of Life magazine in the early 1940s.

• Probably the first practical application of HDRI was by the movie industry in late 1980s. In 1985, Gregory Ward created the Radiance RGBE image file format that was the first (and still the most commonly used) High Dynamic Range Imaging file format.

• Steve Mann and R. W. Picard first reported the process of tone mapping together with bracketed exposures of normal digital images, giving the end result a high, often exaggerated, dynamic range, in 1993. It resulted in a mathematical theory of differently exposed pictures of the same subject matter that was published in 1995.

• Paul Debevec, in 1997, presented this technique of combining several differently exposed images to produce a single HDR image to the computer graphics community.

For more information, visit www. debevec.org/Research/HDR/.

Resources • www.hdrsoft.com (developers of Photomatix) • www.luminous-landscape.com • www.outbackphoto.com • w w w . p o p p h o t o . c o m / howto/3038 Photographers may also look at zillions of HDR shots at some of the more than 15,000 HDR groups: • www.flickr.com/groups/hdr • www.flickr.com/groups/myfirsthdr

Photomatix Pro is available for download from www.hdrsoft. com. A trial version is available. The full version costs $99.

Photo by Kevin Scherer

The High Dynamic Range process “turns a ­simple photo into a work of art.”

Arthur Ng

Making multiple exposures one Create a single image with more range than any of the original images.

By Bradley Wilson

A

s versatile as they are, even the best digital cameras on the market cannot record all the detail in a given scene. Some of the brightest shades or some of the detail in the shadows will be beyond the reach of the properly exposed image.

As Tom Ang, a specialist in travel and digital photography, said, “When people say something is ‘high dynamic range,’ what they actually mean … is ‘The scene’s range of brightness is too large to record all the details we want, given the camera gear we have.’ ” Some shots, for example, have great detail in the midtones but lack detail in the highlights (the light areas), the shadows (the dark areas) or both. HDR techniques combine different exposures that include exposures for the highlights, midtones and shadows to capture a wider range of brightness in the scene than can be recorded by the camera.

In essence, you cheat. You combine three exposures to do what one could not.

True HDR images combine two or more images that are identical apart from being exposed at different levels — the bracket-

42 • Communication: Journalism Education Today

ing exposures.

However, claims such as “HDR increases the dynamic range of your photographs” are not helpful. As Ang said in an online article about HDR photography, “HDR does nothing of the sort. What it does is to squeeze (compress) the dynamic range in the scene so that it fits into what your photograph can show.”

Jack Howard, author of “How To Create High Dynamic Range Images,” explained it this way: “HDR imaging combines several shots of a given scene to overcome the exposure range limitations of traditional single-shot photography — and the final results have much more detail from shadows to highlights and everywhere in between.”

Some of the results — and there are tens of thousands of examples online at sites such as flickr.com — are spectacular. Some are less than awe-inspiring. And some are downright nauseating. Hence, the controversy about the technique.

Indeed, there are even Web sites devoted to the misuse of the HDR techniques.

“Like all techniques, HDR can give stunning results,” Ang said. “And it can Fall 2008

HDR photography relies on three exposures, one for the highlights (left), one for the midtones (middle) and one for the shadows (right). The three exposures are combined to create an image that displays a range of colors beyond what any one image could have diplayed. The exposure for the midtones would be the best of the originals. Photo by Mark Murray

give questionable results that look, to Tips For Shooting HDR some eyes, artificial or too painterly. But BY JACK HOWARD, www.popphoto.com each to their taste.”

• Use a tripod. Even the slightest moveLike many “new digital” techniques, ment of the camera between exposures the digital version of HDR has its roots will be noticeable. in the darkroom where photographers • Auto­bracketing will work, but use the would combiggest EV increbine photos to ment your camera produce results allows. unobtainable on • If you want any one negative. more than three “By the way, source images, this is not new,” keep your aperAng said. “In my ture and ISO condarkroom days, stant.

Change we were known your shutter speed in full-stop incre(if rarely) to ments from a virtushoot a landscape ally black frame at two exposures, to an almost then print the completely white foreground part frame. with the heavy • M o v i n g negative, swap objects will be negatives and “ghosted.” Still print the sky. subjects work But, boy, was it best.

Watch for an awkward, fidcars, pedestrians, dly thing to do.” etc. moving in And it’s not HRD image created using Photomatix and Adobe between expoPhotoshop. Photo by Mark Murray necessarily easy. sures.

“It is easy to • Dramatic differences in colors and “texmiss a step and get frustrated and contures” seem to work well in HDR. fused. Believe me, I know this all too Choose subjects that have good color well,” said Jack Howard, a freelance phodifferences and good contrast between tographer based in Central New Jersey. natural and/or manmade textures “But with a little practice, experimenta• For exposures longer than 1/15 sec, use tion and learning the HDR workflow, you Mirror Lock-up if your camera offers it to may find yourself rewarded with great minimize camera vibration during the HDR images.” n exposure.

Fall 2008

The Weir at Linear Park

By Arther Ng WHY

I love dynamic and saturated colors, and HDR images exactly express how I feel a work of art could turn out to be from a normal photo. To me, HDR brings out the best in my shots and represents my view of photography in another level.

HDR is a way for me to recreate the same moment when I took the shots — however, in a magical feel I want it to be at that time of processing. For this particular shot, it would look plain without HDR processing, and most would simply brush it off as a normal long exposure shot. However, HDR processing turns a simple photo into a work of art.

HOW

To create HDR, I normally take a standard three-exposure shots (-2..0..+2EV) using my Canon Rebel XTI with the default kit lens EF-S 18-55mm lens and with my tripod. I use Photomatix to create a base HDR image with the three-exposure shots followed by Photoshop post processing.

Photoshop work included • Adding a layer effect of “curves” to increase the contrast • Adding a layer effect of “saturation” of yellows and blues for the splash effect • Applying Unsharp mask to the background layer

Born in Singapore, Arthur Ng works as an IT project officer at the University of Adelaide, South Australia. artherng@yahoo. com.au Communication: Journalism Education Today • 43