How to use the iPhone 4 iOS4.1 HDR camera
Apple has done it again with the iPhone 4, pulling a very cool feature out of thin air. This time it is the addition of an HDR (High Dynamic Ratio) function for the already cool iPhone 4 camera in the 4.1 update.
HDR is a fairly new innovation in digital cameras. It is a series of techniques that that allow a greater dynamic range of luminances between the lightest and darkest areas of an image than standard digital imaging techniques or photographic methods. It allows the camera to pull things out of the shadows, for example, when an image contains both very light and very dark areas.
The switch to turn HDR on and off is at the top center of the camera display. This is illustrated by the screen capture at the top left of this article. Touching the HDR control toggles it from Off to On, or vice versa. There is also a new setting under “Photos” in the settings menu, at the bottom of that screen which allows you to keep or discard the original, untouched photo as taken as well as the HDR-processed image. I have elected to keep the original so that I can see what differences exist between it and the HDR version.
The HDR software essentially blends the best parts of three different exposures into a single photograph with a wider range of exposures than the original. This gives you a better photograph in a lot of conditions. Consider the photo below, taken with HDR turned off:
As you can see, it is an indoor photo taken at night. The lamp is so bright that there is almost no detail in the shadowed areas, essentially washed out by too much contrast. Now look at the HRD version of the photo below:
The quality of the photograph is greatly improved, with the lamp toned down a little and the surrounding art objects captured with much better exposures.
You don’t really have to do anything. Just turn HDR on when you think you need it and the camera does the rest. You will notice a lag after the photo is taken while the HDR software make three bracketed exposures out of the original photo, then does its magic to blend those three into a more balanced dynamic whole.
This is pretty amazing stuff for a cell phone camera. The images that I have captured using HDR in difficult lighting situations have improved the end result every time, with varying degrees of success. Most of them have been significantly better than the photo would have been without HDR. Think of it as a new toy within your favorite toy, available with a single touch of the screen.
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September 10th, 2010
Great write-up! Best explanation of the new feature I’ve read yet. I wonder if it affects the size of the photograph? Definitely going to be playing around with the HDR…