What Does Equivalence Mean in Photography?

Back in the film days, nearly every photographer learned on 35mm film cameras, and this was the standard that most enthusiast and even a lot of pros used. Consequently, just about every photographer was familiar with how the 35mm film format would turn out in their final images. Digital has changed this, and we are now seeing a multitude of sensor sizes and formats on the market. This has created a lot of misunderstanding on how to get an equivalent image between different systems. For example, is it possible to obtain the same field-of-view, depth-of-field, and overall noise between Micro Four Thirds, APS-C, and full-frame cameras? Many photographers would assume the answer is no, when in fact it is possible (within certain limitations, described later). In Photography, this is known as equivalence. Continue reading “Equivalence”