One stop of light can be either added to a shot or taken away in one of two ways. One can either double or halve the shutter speed, or double/halve the aperture. Because of this relationship, if you’re light meter gives you one reading, you can translate that reading into another. For example, if your light meter gives you a reading of 1/30th second at f/8, and you want something with a more shallow depth of field, you could open your aperture three stops to f/2.8 and stop down your shutter speed to 1/250th second, for the same result, but with more depth of field.

Now that we have the established relationship, it’s good to talk about how a light meter reads a scene. The light meter’s goal is to make a perfectly balanced, middle gray scene. Middle gray is the value halfway between 100% white and 100% black. Your light meter will take all the values in the given scene and average them, that value becomes the scene’s middle gray, and the light meter returns a result to achieve a “balanced” image. Because of this, sometimes it is necessary to override it’s suggestions to get the desired shot. If your subject happens to be lit so that their tones are in perfect middle gray for the scene, than great, but more often than not, they will either be lighter or darker. Thus, if your subject is lighter than middle gray, you’ll need to overexpose a bit, and if you’re subject is darker than middle gray, you will need to under expose.

Better cameras now come equipped with histograms. A histogram plots out on a light from 100% black to 100% white, where the majority of values lie. It can be very helpful to discover exactly where you should adjust your settings to in order that what you want to be middle gray, is.

Exposure can be very useful in capturing exactly the photo you desire. Your exposure can make that same shot feel peaceful and serene or violent and chaotic.

Journaled Time: 4 hour – reading, research and taking notes
Total Class Time: 14 hours