Determining Exposure

By: Alain Briot
1 - Introduction
Exposure. The word 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.
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! Then what? Is there a way out, a way back to a great image despite the fact you could have done better in the field exposure-wise?
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?
So many questions and, I am afraid, so few answers. Exposure isn’t the most widely discussed subje...