Tuesday, December 4, 2012

Learning a new word: HDR (ok ok, so it’s not a word…)


It dawned on me this morning that, not only am I now a full time photographer, but by default, I’m also a full time blogger. What does this mean? It means that now I have both a creative outlet for making images but also now an outlet for sharing the stories behind those images!
Case in point…High Dynamic Range imagery, or HDR for short. I find the majority of people I ask don’t know what an HDR image is, but unbeknownst to them, they’ve probably been looking at HDR type images all their lives. More on that later.
Creating an HDR starts with making multiple images, all shot at different exposures, and then using special software and algorithms to blend the images together to create one beautifully exposed final image.
The different exposures are meant to bring out details based on the light levels of the given scene. For instance, a scene with high levels of contrast (the areas between bright highlights and dark shadows…and everything in between). A normal camera, or even a very high end camera, has difficulty exposing for all these different ranges of light at the same time. You may expose that beautiful blue sky perfectly, but the people in the picture (the ones standing in the shadows of a tree for instance) will come out to dark. Or perhaps you’ve experienced the classic “blown out sky” syndrome…..you take a picture of the kids in their Sunday best and the kids expose perfectly….but that blue sky is suddenly white? What happened? That’s known as blown highlights, and while it’s considered “normal” in many situations, it’s far from desirable.
With HDR images, we would make a minimum of 3 different exposures. In the scenario mentioned above, we would shoot one exposure for the sky (the highlights) the kids in the shadow of the tree (the shadows) and one exposure that’s kinda-sorta in the middle range (that’s the technical term for ‘take a normally exposed image).
Now to create our HDR.
Below is series of images I took of my children horse playing. Because I needed at least 3 images for the final HDR picture, I had to shoot quickly because they were moving. A lot.
3 exposures
Notice the three different exposures below. With my camera in MANUAL MODE, the first one is OVEREXPOSED by about 2 stops, the second exposure is UNDEREXPOSED also by about 2 stops, and finally the third image, which is basically a ‘regular’ or normal exposure just the way the camera originally wanted to take the picture.
Next comes the fun part. I open a program called Photomatix and I drag & drop the three images into that program. From there it’s just a matter of agreeing to various settings and then adjusting the image to taste. Once you get the picture to look the way you want it, hit <PROCESS> and then save the image to your folder of choice.
And that’s it! We’ve made our HDR image. It was fast, it was fun, and the details are fantastic. Here is the final image.
IMG_6299_-2_-3_tonemapped
I should point out that I am in no way affiliated with the Photomatix software or HDRSoft, the company that puts out the software. However I am a huge user of it and I’ve been with them since the very beginning. The software has gone thru tons of updates over the years and it continues to get better and better with each update. It’s highly recommended.
So there we have it, HDR photography. This post just scratches the surface of what is possible with HDR photography. I encourage anyone to give it a try. The software runs $99 so it’s a very inexpensive but powerful way to get into this fascinating type of photography.  Below are some additional HDR images I shot over the years. Some of them exceed the ‘three exposure rule’, in fact some of them are up to 15 separate exposures!
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