This morning on Facebook I saw a post from a friend of a friend who was having some challenges getting good results with pictures taken in the snow. Let's face it, snow is pretty, but it poses more challenges than just being wet and cold, the biggest of which is that it's white. White snow reflects light very effectively, and can easily cause your shots to be over-exposed. When a picture is over-exposed, you can quickly lose contrast, and the fine details get lost in the bright light.
So how can we mitigate the problems of snow?
Metering
The first step is to check whether your camera has different metering modes. Metering, for the uninitiated, is process where the camera measures the light in the scene, and decides how to set up the camera for a particular exposure.
The metering modes available on my camera are:
- Evaluative - This mode looks at the light from the entire scene, and adjusts accordingly. Unfortunately in snow, this mode can also be thrown off by the fact that the background is extremely bright.
- Partial/Spot - These modes only consider the center of the image when calculating the proper exposure. This is one of the best modes to use with bright backgrounds or back lit subjects.
- Center Weighted - This mode evaluates the entire scene, as with evaluative, but gives more weight to the center of the image.
(Your camera may have different modes, so refer to your camera's manual for help.)
With the built-in meter, you may have to measure the light on your subject, then set the camera manually to match the specifications. If you're shooting a centered subject in a program or automatic mode, then you don't have to worry. If, however, your subject isn't centered, make sure to meter your subject first, lock in the camera's settings, then compose and take your shot.
Exposure Compensation
Exposure compensation is an augment to the meter. Essentially what it does is tell the camera to consider a different light level to be the 'well exposed' level. With bright scenes, you can adjust the level down, and the camera will automatically select settings for a darker shot.
Bracketing
Bracketing is the process of shooting a picture with multiple exposure settings. You can do this manually, but many cameras can do it for you automatically. Basically the idea is to take a shot, then take one with settings that will produce a darker exposure, and finally take a shot with settings for a brighter exposure. (You can also take 5 or more bracketed exposures, but good luck keeping your subject stationary long enough.)
HDR
High Dynamic Range (HDR) is a technique, like bracketing, that takes multiple exposures at different brightness levels. The difference is that once all the images are collected, they are combined together into one final image. With HDR you can take an image with very dark parts and very bright parts, with both being well exposed.
If your camera can't do this on its own, there is processing software available to merge the images together. Just shoot bracketed exposures, and then use software on your computer to merge them.
Filters
Filters are the things you can screw onto the front of your lens that modify the light coming in. If you find that no matter what you do, you end up with an over-exposed shot, consider picking up a Neutral Density (ND) filter. The filter doesn't affect the color of the image, but will reduce the amount of light coming into your camera.
Side Note: ND filters also allow you to take longer exposures than you'd ordinarily be able to take, so they can be useful for daytime exposures where you want some motion blur.
White Balance
Ok, so we've looked at adjusting for brightness, but what about color. Ideally the snow in your image is bright white. If it comes out tinted yellow or red, check the white balance settings on your camera. Most cameras are pretty good about selecting an appropriate white balance, but your preferences may differ from the selections made by the camera. For shooting outdoors in bright sun, make sure that your white balance is set for daylight. In the shade, select a shade setting. If that still doesn't work, many cameras offer you the ability to dial in the exact color temperature that you want.
Software
The last option is editing software. You can adjust the exposure and contrast of the image, and may be able to fix marginal images. Remember though, that software isn't magic, and can't work with things that aren't there. If your photo is extremely over- or under-exposed, you may find that there's no way to fix it.
Conclusion
Shooting in the snow can be rewarding, but can also be frustrating. The only way to really nail the exposure is to go out and practice.
