A number of folks have recently asked about HDR Photography: how it works, what’s the best software out there to use.
Here’s a very simple premier on the subject. HDR allows the camera to see the world the way us “humans” do. For example, while you can easily see your friends on a beach looking into a setting sun, your camera can’t. The dynamic range between the bright sun and your buddies is too great (resulting in a silhouette style photo). Likewise, most nature shots either expose the sky properly (with the foreground too dark) or the foreground ok (with the sky blown out).
HDR to the rescue! In the example below, I’ve taken three shots (Zion National Park: shot A is 2 stops under exposed, shot B is neutral and shot C is 2 stops over exposed.
Our first shot renders a pretty good sky, but the rest of the photo is really dark! Eckkkkkkk
Our next shot is done at neutral exposure. The foreground looks better, but still pretty dark and lifeless. We’re also starting to lose sky detail.
Now to try 2 stops overexposed. The foreground looks better, but the sky is totally blown out…almost stark white.
Now lets put HDR software to work. HDR programs take the best pixels in each of our three photos and merge them into one magnificent blended image. Err…at least that’s been the theory. Much of the earlier HDR work was done directly in PhotoShop. The results were ok, but had a rather unnatural look them
Then came Photomatix, which was until recently the industry standard. The photos looked more lifelike, but many professional photographers frowned upon the results often with good reason. Many Photomatrix prints looked surreal and phony with lots of ghosting and unnatural artifacts.
The Photomatrix rendition of our print below isn’t half bad however. It’s certainly a big improvement over any of our three former pics.
A new program called HDR Expose has recently become available. As you can see the results are both more realistic and more impressive. http://unifiedcolor.com/products/hdr-expose-3
Some parting technical advice (Q&A):
1. How do I take the bracketed shots (2 stops apart)? Ans. Most DSLRs can be programmed to take 3 or more bracketed shots. You’ll want to be in Aperture Priority Mode so the F stop stays the same for each photo. Ergo, the shutter speed is the only variable to change. Why not change the aperture? Because if you merge 3 photos with different f stops, you’ll also get different depths of field in each image… the result can look blurry/odd.
2. Why 3 bracketed shots…is 5 better? That depends on the dynamic range of the situation. For the photo above, the difference between the brightest and darkest section was about 11 f stops. 3 bracketed shots was fine. If on the other hand, your taking an indoor shot and want to have the exterior view out the windows correctly exposed, you’ll likely need to bracket 5 shots.
3. Will my camera bracket 5 shots…Ans. depends on the model. Most full frame DSLRs will bracket up to 7 shots, sadly entry level/amateur DSLRs are limited to 3.
4. Tripod? You can certainly do great HDR handheld! The best approach: set your camera for 3 bracketed shots (2 stops apart) and adjust your drive mode to high speed burst. When you depress the shutter the camera will knock off three quick bracketed shots and then cease shooting. Remember to hold the camera as steady as possible and be gentle when depressing the shutter button down. Most full frame cameras in high speed drive mode shoot a reasonably high burst rate (Canon 6d 4.5 shots/sec, 5DMKIII 6 shots/sec). If your shooting with a IDx don’t worry it’s 12 shots/sec!
Notwithstanding the above I always try to shoot HDR photography with a tripod. Two reasons: I: I’m usually looking for maximum depth of field and need the stability to use small apertures. II: HDR Expose has a special “fixed camera” processing option that virtually eliminates noise (particularly in those dark area prone to the problem). My results look sharper on a tripod.
5. When to go “old school”. HDR is great in many situations, but sunrise and sunsets are important exceptions. Most colored skies taken when the sun if low look very artificial and overly contrasty in HDR…or as I like to say “resemble a science experiment gone wrong”.
Try using a graduated neutral density filter instead. You’ll get much better results and retain the beautiful colors of the early morning sky (or sunset).
Good luck and happy shooting!