The Exposure Triangle

Photography and video are important components of instructional design. As we look at some of the things that photography can help us with regarding good visual design overall as well as good instructional design it would be a mistake not to share one of the more important photography concepts.

This is the exposure triangle. We’ve all seen images that were overexposed and a bit too bright and images that were a bit underexposed or a bit dark. So today I wanted to discuss the three elements that make up the exposure triangle in photography.

The first element is the shutter speed. This is literally the speed at which the shutter moves out of the way and lets light pass through to the film or these days to the light sensor. The slower the shutter speed the more light but also the more likely that images seem blurry due to movement.

The second element is the aperture. The camera’s aperture works just like the pupil in our eyes, it opens and closes to let in more or less light. We discussed this a few days ago when we discussed the depth of field, the trade-off with light and the aperture has to do with the depth of field your image sill have.

The third element is ISO. ISO can be a bit confusing but it refers to the light sensitivity of your film or the artificial light enhancement done in the computer part of your digital camera.