EXPAND TONAL RANGE IN RAW

In his continuing series of Digital Darkroom articles, Jon Adams explains how to capture the full brightness range of a scene in multiple shots, and then blend them together in Photoshop CC as an HDR image.

The dynamic range (DR) of a scene extends from the brightest to the darkest areas that still reveal some detail. On scenes with a very high dynamic range, it’s not possible to capture the whole range in a single exposure, because a digital camera’s sensor simply can’t do it. With a scene which contains a bright sky and a dark foreground, you can set the exposure to record details in the brighter highlights but which will throw the shadows into obscurity. Alternatively, you can add more exposure to record the shadow detail, but which will then blow out all the bright areas to pure white.

To get the best of both worlds, you can shoot multiple exposures to record detail across the entire tonal range, and then blend them together to create a high dynamic range (HDR) image. This gives a picture that’s closer to the way the human eye would perceive the scene, as the eye can take in a much bigger dynamic range than a camera.

RAW files already possess a wider dynamic range than a standard image file format like a JPEG, and this extra detail can be revealed by adjusting the settings in a RAW converter such as Adobe Camera RAW or Lightroom.

A recent addition to this software’s engine allows you to shoot multiple exposures at different values and then combine them together to get a special, HDR RAW file. You then process this just like any other RAW, and use the expanded dynamic range present to create striking images that retain a natural look. So let’s look at how to set up your camera to capture a multi-exposure HDR sequence, and how to process the shots in Adobe Camera RAW.