There’s no denying that snowscapes present some wonderful photo opportunities. They also present us with some issues – specifically exposure. If you allow your camera to control exposure in the snow the chances are you’ll end up with some distinctly underexposed pictures. There’s also a good chances you’ll see a distinct blue cast. This is because snowscapes aren’t average scenes, and when a camera calculates exposure, it’s expecting an average scene. It’s expecting the distribution of light and dark and the balance of colours to be somewhere around grey. In a snow scene however, the average is pretty much white. So the camera needs to be told. The simplest way to do this is to bump up the EV (Exposure Value), which either slows the shutter speed or increases the lens aperture.
The picture above was taken with exposure set to Program mode, which calculated an exposure at 200ASA of 1/250th at f8. You can see from the image that the snow is less than white. Compare this with the photo below.
In this photo an Exposure Value of +1 was dialled in, resulting in both a larger aperture and slower shutter speed, 1/160th at f6.3. The difference is quite pronounced and gives us a truer representation of the scene.
Almost all modern digital cameras from dSLRs to compacts allow you influence the exposure using EV. Many use a dedicated button on the back of the camera, usually signified by a +/- symbol. You can use this creatively for any number of not-so-average scenes, from snowscapes to shooting into the sun. So if you find that using the cameras n=built in metering gives photos that are to dull or missing shadow detail, think about using the EV control to adjust the exposure.