Pixiq

The number one question I am asked regarding exposure is how to expose correctly for snow.  If you don't understand exposure and you take pictures of snow scenes without any kind of compensation, the pictures will be dark.  The reason this happens is because all light meters are programmed to read middle toned subjects like green grass, blue jeans, red flowers, and skin tones.  These subjects will give consistently good exposures.  However, if the subject is primarily white, like snow, the meter sees it as middle gray and consequently underexposes the photo which makes the snow gray.  This isn't what you want.

Many photo instructors teach that you should compensate for this underexposure by overexposing the pictures by a certain amount.  This ranges from 1 1/3, 1 1/2, or 1 2/3 f/stops, depending on the instructor.  I disagree with this formula because there can't possibly be one remedy for all snow situations.  After all, there are snowy scenes in diffused light, in sunrise and sunset lighting, and in mid-day sunlight, and one compensation formula can't work for all of them.  In addition, there are situations where only part of the frame is white, such as when a meadow is covered in snow but the upper portion of the image consists of primarily bare trees or blue sky.  An example is the shot of the wolf below. How can this formula work for this kind of shot as well as when you are shooting in a snowstorm and everything is completely white? Obviously it can't.

There are four ways you can expose for any kind of snow situation and be consistently correct.  This includes white-out conditions like the Yosemite landscape, above, and the mountain lion shot in which the center of the frame is middle toned while the periphery is white.

1.  Use a hand held meter and use it's one-degree spot mode function to read something middle gray in the scene. In the case of the mountain lion, that would obviously be the cat itself.  In the barn photo below, you could use the weathered wood or the deep blue sky.  For the tree in a snow storm where there is no white area at all (the photo below the barn image), I use my middle toned camera backpack or a gray piece of fabric sewn onto a photo vest. Once that reading is determined, I would then set the camera to manual exposure mode and choose the f/stop and shutter speed dictated by the meter to take the picture.

2.  Use the incident function on a hand held light meter.  This is the white dome, and it reads the light falling on the scene as opposed to the light being reflected from it. Therefore, it is not adversely affected by how a subject or scene is reflecting light.  The incident meter is used by pointing it at the camera, and it must be held in the same light as the subject being photographed.

3.  Use the built-in meter in the camera on spot mode and read a middle toned portion of the scene in front of you.   Lock that reading in place using the AE lock button on the camera and then shoot.  After the first shot, the camera unlocks the meter and you can then read another scene.

4.  Take a shot and then look at it on the LCD monitor on the back of the camera.  If it is too light or too dark, simply tweak the exposure using the exposure compensation feature on the camera in 1/3 f/stop increments.  If you don't know where this feature is, consult your instruction manual.  It is one of the most important features on your camera.