High Dynamic Range

OK, for the past few years people have been working with high dynamic range (HDR) post processing. After posting a couple of HDR images on Facebook (you can find it here.) I’ve had people ask exactly what is HDR. They can see the images look different than a traditional image, but can’t put their finger on it.

To properly explain it, we need to briefly talk about Dynamic Range. Dynamic range relates to how film or a digital sensor sees the bright and dark elements in a scene. Let’s look at the image below.

Lab Coat - standard digital image

The image above is a standard digital image. In a photo in which there are bright highlights (the white lab coat) and dark areas (the bottom third of the image) we can see that, if we want to see detail in the shadow areas, the white lab coat would get completely blown out.

To get around this we could add lighting to fill in the shadows. But an interesting alternative is use HDR. HDR is achieved not by shooting one photo, but by shooting several at different shutter speeds. You cannot use different apertures, because it will cause issues with your depth of field. Then you composite the images together with your editing software, revealing just of the parts of each photo in which there is level of detail you want.

Labcoat - processed for HDR

In the photo above, notice the increase it shadow detail over the first image. It makes a huge difference. The technique works best in very contrasty situations where the dynamic range of the camera is tested.

Experiment with HDR, it creates some interesting looks. Also, remember to use a tripod so all the images line up.

Thanks for reading!

-Ken.