In the world of digital photography is the Sunny 16 method of determining exposure still useful? Sunny 16 was a tried and true method of guestimating exposure by the time I bought my first 35mm SLR. That camera had a very simple light meter at was easily fooled. If you didn’t know that your light meter could be fooled, quite often your exposures would be off. By knowing how the lighting conditions effected your exposure you could tell when your meter was “telling porkies” that would cause you to over or under expose your images.
What is Sunny 16? Sunny 16 is a way of determining an exposure based on the ASA (predecessor to ISO) you were using and the conditions that you are shooting under. Sunny 16 states that on a sunny, cloudless day, with your subject in full sun, your shutter speed will be the reciprocal of your ASA at f16. So, if you were using Kodachrome 64 (64 ASA) photographing cars on a bright sunny day your exposure should be close to 1/64 second at f16. It was also helpful in determining an exposure in other outdoor lighting conditions. Take a look at this chart:
Bright or Hazy Sun on Light Sand or Snow f22
Bright or Hazy Sun, distinct, hard edged shadows f16
Weak, Hazy Sun, soft edged shadows f11
Cloudy, shadows that are barely visible f8
Full overcast, no shadows f5.6
Open shade and sunset f4
With digital cameras is this information still useful? Yes, it can be. With all the technology that now comes packed into your camera, Sunny 16 will still help you out if your camera’s meter has been fooled. Let’s say your subject is a brightly colored wall. If you make an image based on what the camera’s meter said, it will probably come out too dark. Your camera’s meter wants to turn everything the same tone as 18% gray. So how much should you adjust your exposure? If you have already made one image looking at the image information is a good place to start. Lets say your image info tells you the shutter speed was 1/200th of a second and the aperture was f22. The wall is in full sun and your ISO is 100. Well, right off you would know that you are 2 stops under exposed. Sunny 16 would give you an exposure of 1/100th of a second at f16. You adjust your exposure and the next image looks great. Next you want to photograph a dark colored door knocker on a black door that is also in full sun. This time your camera’s meter says you should expose the image at 1/50th of a second at f11. Now your camera wants to over exposed the black door by two stops. Knowing this you quickly adjust your exposure to 1/200th of a second at f11 and the image looks well exposed when you check.
Keeping Sunny 16 in mind while you are making images will help you make better exposures, the first time, because you will know when your camera’s meter has been fooled and the camera is telling you porkies.