Normally, digital cameras process image data captured by the sensor and save the finished photo as a JPEG file, but RAW files contain the image data in its unprocessed form. You need a program capable of processing these RAW files on your computer, but the advantage is better image quality and the ability to choose some of the settings later rather than having to commit to them when you shoot.
Adobe Photoshop and Elements come with the best-known RAW converter, Adobe Camera Raw, but iPhoto is perfectly capable of processing RAW files too. In fact, it’s rather good at it. The tools are much more basic than Adobe Camera Raw’s, but it generates good definition and colour, and it’s especially effective at recovering highlight detail, as we’ll see.
If this photo was a JPEG, adjustments would slowly degrade the image. But as a RAW file, edits are non-destructive.
Mostly, RAW files are handled in just the same way as JPEGs. You’ll see a ‘RAW’ badge in the corner of the histogram at the top of the Adjust panel, and the adjustment tools are the same except for two key differences. The first is that the Exposure/Recovery slider can pull back data that’s disappeared off the right-hand end of the histogram scale. With normal JPEGs, these highlights would be lost for good.
The second difference lies in the White Balance section. With JPEGs, the white balance is set by the camera, which discards leftover colour data; the Temperature and Tint sliders just apply adjustments to the remaining colours. But RAW files contain the full colour data captured by the sensor. The Temperature and Tint sliders now show the white balance set on the camera, but you can change this to match the shooting conditions.
It’s possible to get much better results from RAW files than JPEGs. Let’s look at them in more detail.
