Apple iOS 4.1 HDR iPhoneography

Capturing the bracketed exposures of iPhone's new HDR


Apple released the iOS 4.1 update for iPhone on Wednesday. Among the new features is HDR (High Dynamic Range) for the Apple Camera. Among the questions when the feature was introduced by Steve Jobs at the iPod event was if it is true HDR or is the camera using “sleight of hand” and simply tweaking the exposure of one capture.

The new HDR feature is true HDR. The camera takes three bracketed exposures — one normal, one slightly overexposed, and one slightly underexposed — and merges them together, keeping the best exposed areas of each capture. Shadows can reveal more detail without blowing out the highlights. In theory, images should also have reduced noise. The test image above shows artifacts from a moving object (my hand) where the images merged. In the circled areas, you can see through my fingers on the merged, HDR image. Although you only hear one shutter release sound, the speed in which the iPhone 4 camera is taking three captures is impressive. By the way, my test image is only to test for three exposures — I realize that it sucks as far as showing the shadow, highlight and color improvements of the new HDR feature.

The new HDR feature is only available in Apple’s Camera app on the iPhone 4. Third-party photo apps which use an API call to the iOS camera aren’t able to access the HDR feature. It’s an optional feature and can easily be toggled on and off in the viewfinder.

I’ll have a full test of the new Camera update soon. So far, I’m really impressed with the performance of the new updated Camera app.