For the context of this discussion DR (Dynamic Range) is the range of light values that your camera can process. Your camera isn’t capable of anywhere near the range your eyes are, so this can present challenges to you, the photographer.
Images with blown out (overexposed) clouds and completely dark shadows are a common problem for photographers. Each device you use to view your photos: camera; PC or laptop monitor; printer; print, can affect the way an image looks. A piece of white paper is truly only as white as the light that’s illuminating it at the moment you look at it. Your camera and computer monitor are probably about the most consistent sources of light you have to view your images with. Prints are affected by the light in the room you are in. Fluorescent lighting can make them look greenish, incandescent yellow and so on.
Back to DR. Dynamic range is measured in EVs (Exposure Values) or, in the case of most people speaking photography, F-Stops. A really great site for seeing tests on cameras is DXO Mark. DXO Mark tests lots of cameras. If your interested in specs on your camera, you should pay the site a visit. According to DXO Mark, a DR range of 12 EVs is outstanding. Even that though does not compare to the biological wonder that our eyes are. We have two eyes to register scenes with. Beyond what our eyes can do with the light that hits them, our brain does even more so that we perceive something in a way that cameras are a long way from being able to achieve. DSLRs however are far superior to film, so who knows what we will be shooting with in the next few years. When I look back at what I could do with film and what I am able to accomplish now with digital images and Photoshop, I am truly astonished. 4000p televisions are available and from what I have been reading it looks like 8000p and greater is not far away. These new standards will drastically increase dynamic range and camera manufacturers will most likely be adapting very soon.
The point of this post is simply that your camera is not quite capable of capturing all the levels of light in every scene that you point it at. When you see the sun setting over the ocean, your mind’s eye has an image of the entire scene, but your camera may see a dark body in front of a very bright light source and mess it up for you. You have to learn how to compensate and not lose the light from either end of the DR spectrum. For scenes with really high contrast, you can learn about neutral density filters and High Dynamic Range imaging.
I’ll be adding more posts soon about shooting techniques we can use to capture a scene that more closely reflects what we see in our mind when we press the shutter button on our cameras.
For the casual shooter with a point and shoot, making an image is a one step process. For the serious photographer however, pressing the shutter button is only the beginning of a truly enjoyable multi-step, artistic process aimed at bringing out the very best of each RAW image your camera captures.