Relevance of Exposure

Tranquility
Canon 5D Mark II, f/10, 1/640, ISO 100, Exposure Bias -0.7 Stop, Partial Metering

What is exposure?

Exposure, in photographic terms, is the process of capturing light with your camera to produce an image on a film or a digital sensor. When we look at something, our eyes adjust very quickly so we can see it properly. With exposure in photography, things are very similar. There are two functions that matter here. One is the ability to adjust to the brightness of the subject and the other is adjustment to its distance from us (Focus).

To professional photographers, exposure holds great concern as it contains a certain notion of risk and a certain amount of irremediable commitment. Once the exposure has been set on a camera and the subsequent photograph taken there is no way to physically change this exposure. You are done, set and have to live with the consequences. Hopefully the exposure is “right on” and the photograph holds details everywhere.

Ready for the Kill (Indian Pond Heron)
Canon 1D Mark IV, f/8, 1/500, ISO 200, Exposure Bias - 1 stop, Partial Metering

But what if the photograph does not hold detail everywhere? What if your calculated exposure isn’t absolutely, 100% correct? What if your calculations were off, what if you made a mistake! More importantly, in order to avoid post-photographic-exposure stress, how can one calculate, with absolute accuracy, the perfect exposure, each and every time, in the field?

However, exposure isn’t rocket science. There is a certain amount of leeway, adjustment and artistic interpretation involved. The goal of learning how to expose is not only being able to determine the “correct” exposure. Most cameras do this automatically and in many instances we can trust what they tell us. Plus, with the histogram function we can visualize how the final image will be exposed. 

Hide and Seek
Canon 5D Mark III, f/10, 1/800, ISO 400, Partial Metering

The goal of learning more about exposure is to gain control over how our photographs are exposed. Our goal is not only to find the proper exposure but rather to find the exposure which will give us the effect we are looking for. A properly exposed photograph is one we will eventually consider for printing. In this sense such a photograph is what is often referred to as a keeper. But being properly exposed is not enough to make a photograph a keeper. Other things come into play when making this selection such as, shadows, contrast, etc. 

Kazan Cathedral
Canon 5D Mark II, f/20, 15 Sec., ISO 100, Exposure Bias -0.3 Stop, Partial Metering

We shall continue with our detailed articles on Exposure in forthcoming posts.

Happy Clicking!