Photographs, as made by the technology found it today’s cameras, aren’t very good when capturing scenes which have a High Dynamic Range (HDR). Such scenes will typically have areas that are extremely bright, and areas that are very dark. Cameras can do a reasonable job of capturing detail in one or other of those areas, but not both at the same time.

That’s where the concept of HDR photography comes in to play. The idea is that if the camera makes several images, one after the other and each one exposed slightly differently (between one and two stops apart), then collectively they will have captured all the detail in a given scene.

Sophisticated software exists whereby these several images can be overlaid and the software selects which part of each image it will use, or even merge a few images and extrapolate those parts it wants. Tone mapping may also be applied.

Now, enter stage left, the iPhone.

Mobile phones have become part of the everyday lives of many people; in particular, the camera found thereon is used to record minutiae of everyday life. But most mobile phone cameras aren’t very sophisticated – they’re built to a price.

Like their bigger brothers, these cameras aren’t very good at recording detail in the bright and the dark parts on a scene.

That’s where “Pro HDR” for the iPhone comes to the fore, and is worth much more than you pay for it.

In my opinion “Pro HDR” operates best on “live” images – that is to say, in place of the Camera app already found on the iPhone. “Pro HDR”, when operating in automatic mode, will determine the brightest and the darkest parts of a scene, and then make two images, one exposed for the bright, and one for the dark. It then creates a blend of the two to give a single “HDR” version.

So, I purchased “Pro HDR” then installed it on my iPhone 4 (it also works with iPhone 3GS and iPod Touch 4G) and put it to the test.

Three images follow. The first is the image made when exposing for the brightest part of the scene – in this case, the clouds. Details of the clouds are clearly visible.

The next image is one which has been exposed for the darker parts of the image – in this case it’s pretty much everything other than the clouds. As you might expect, the sky is overexposed and lacks detail.

The third image is the composite automatically created by “Pro HDR” and which is an amalgam of the previous two images.

I am impressed! And the cost? $2.49 in the Australian iTunes store. Definitely one the the few real bargains in life.

[All of the above images are as taken by "Pro HDR", no adjustments were made other than to resize the images.]