iPhone's new built-in HDR, gimmick or groovy?

What are the best uses for the newly added camera HDR feature for iPhones? Apple just released a free update to their OS4 software that adds in-camera HDR to the latest devices. HDR, or High Dynamic Range, is a process of combining multiple exposures to achieve a single, highly detailed image. There has been third-party software available via the app store to do HDR, but never has it been quite this easy. There is simply an additional button on your camera screen to turn HDR on or off. By default, when you take an HDR image, the phone saves both an original, non-HDR version and the composite HDR version automatically. You can quickly review both images after taking them to see which you prefer. 

Here's my take on it. It's great. If you know what HDR is actually for...capturing details in extreme highlight and shadow areas of high contrast scenes - details that would normally be lost in a normal, single exposure, then you'll immediately see the benefit and quality difference the new HDR tool provides. HDR is not for every image. A well lit scene, with relatively low contrast, will not pose any challenge for a single exposure. Using HDR may make it appear flatter in contrast (when in reality, under histogram inspection, you'll see a very full white-to-black contrast range). 

Where HDR is great (and where it's intended to be used) is in extreme contrast scenes where your important detail is going to be either blown out in the highlights or obscured and noisy in the shadows. As you'll see in my quick examples and experiment, even if you used desktop software to try to rescue your normal exposure - essentially opening up the shadows and bringing down highlights, in an attempt to match the HDR image, the results will not even be close. The adjusted image cannot touch an HDR image for highlight detail and overall color accuracy and saturation in challenged areas.

I took a walk at lunch today. It is a beautiful, bright sunny day, perfect for HDR play. Let's take a look!

Notice the shadow side of the barn and the brightly lit grass. Click the image to see it larger.Wow! Look at the detail and color in the beams of light. Click the image to see it larger.Look at the sunlit grass in the back. Much more detail is preserved.Lots of preserved detail in the HDR version here. Click the image to see it larger.One of the limits of HDR is when you have moving subjects. Since the camera takes 3 shots sequentially, the subject has to be relatively still or ghosting will appear, as shown.More shadow information and detailsOnce detail is gone, it's gone. No amount of adjustment in software later can recover the lost information, detail, and color.This last pair of images illustrates how even if you took the time to download your images, work them in iPhoto, Lightroom, or Photoshop, you would not be able to "fix" the original image to achieve the level of detail and color accuracy that an HDR image provides. On the other hand, by doing some minor adjustments to global contrast on your HDR image, you'll be rewarded with snappy images that preserve tons of detail from bright highlights to deep shadow.

For creating highly detailed images in camera, with minimal fuss, the new HDR feature is a welcome new tool. Oh, and it's free :-)