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Friday, August 24, 2012

The original purpose of HDR was to allow the photographer to obtain great images in extremely difficult lighting situations


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Of course, HDR has been around for a number of years. In fact, the concept, although not in its present form, has been around since the middle of the 19th century. Until the digital photography age began in earnest in the 1990′s the only methods available to achieve an expanded dynamic range was by the use of multiple negatives to produce a single positive or by dodging and burning in the darkroom. Today, with digital cameras, post processing software such as Photoshop and a myriad of HDR software packages available to the photographer, the application of HDR has become widespread.
The original purpose of HDR was to allow the photographer to obtain great images in extremely difficult lighting situations –for example, scenes with very bright areas and areas with very dark shadows. You know the situations. We’ve all taken photos and looked at the histogram to find the whites and the blacks completely “blown out”. Using all the available tools, photographers being creative types to begin with, have taken HDR to new heights and produce images that look more like drawings or paintings than photographs.
While I’m not a fan of the “extreme” HDR images, I still find it fascinating what people are doing with the available tools as shown in the following three images.
Here the photographer remained closer to a photograph than a graphic arts image. With the camera pointed at the building and the sun behind the building, without HDR the building would be no more than a silhouette unless the sky was so overexposed that it had no detail at all. By creating an HDR image, the entire scene is recognizable and detailed.
In this image, the photographer has employed a few more adjustments to the image to the point that while everything in the image is recognizable and clear our eyes tell us that this isn’t really what the scene should look like. In this case the photographer has taken the image to the point that it’s somewhat unrealistic. Still, a nice image.
I call images like this one cartoonish. I don’t mean to be derisive by that description. It’s just that, to me, the photographer has made adjustments in post processing that take the image beyond looking like a photograph into looking more like what you might see in a comic book. Not my cup of tea but there are many, many photographers and observers that really like this treatment and there sure isn’t anything wrong with it.
I almost always use HDR for sunrise and sunset photography. Here are three exposures of a shot I took one morning in the Everglades. The first is the exposure the camera “read” set on Av or aperture priority. The second image was underexposed by one and one-third stop (faster shutter speed) and the third was overexposed by one and one-third stop.
No secret, I use Photoshop, right now CS5. I also use Nik software plug-ins and for the HDR images I used HDR EFEX Pro which is the Nik HDR software. Keep in mind that there are numerous HDR software products on the market and each gives a somewhat different rendition. I know some photographers that use three or four different products to create the image they like the best.
In the first paragraph I mentioned that before the digital age of photography really took off, there were only two ways to achieve an expanded dynamic range; dodging and burning using a single negative and the use of multiple negatives to produce a single positive. Guess what? That’s still pretty much the approach still today. The two methods are called Tone Mapping that uses a single image to create a HDR image (dodging and burning using a single negative) and Merging that uses multiple images to create a single HDR image (multiple negatives to create a single positive).
This image was created by Tone Mapping the “correctly” exposed image. This approach is especially useful when trying to create an HDR image from a scene that has a lot of movement like a street or beach scene.
For this image I utilized all three of the images above and the software merged them into a single image. For both images I selected the “Realistic (strong)” preset. There are many other presets such as “Vibrant Scenery” used in the next image. Of course, the software also allows the photographer to make his or her own adjustments to create the “look” desired.
Which one is best? There isn’t any right or wrong answer. It’s up to the viewer. I prefer the merged image with the Realistic Strong preset, but that’s just me. Besides, I was there and remember what the scene looked like and what I wanted to capture and the way it appears to you also depends on the monitor you’re using.
HDR is a lot of fun and often very rewarding, turning a so-so image into something really nice. Unfortunately, you almost have to have special HDR software to create the images. It is possible to create HDR with Photoshop CS5 but it requires more steps than most of the add-on products and I haven’t been as pleased with the results as I am with HDR EFEX Pro. If you don’t have HDR software and/or haven’t tried HDR photography, I recommend you put it on your to-do list.
Photo Credits
Gatico-HDR by milivoj on Flickr Creative Commons
Gran Café Zaragozano, Zaragoza, Spain by marco_dmoz on Flickr Creative Commons
Pier by evilaardvark on Flickr Creative Commons
All other photos by Steve Russell

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