Exposure 101

StairsExposure is the amount of light that reaches the image plane and is usually measured in EVs (exposure value). There is no one single correct exposure for a single scene, but some correct and some creative different choices for it. Even though, due to the nature of each sensitive surface, there is a proper way of exposing the capture of it and fine tune the results for the final work after the capture.

In digital sensors the proper way to expose is to keep the brighter zones we want to keep detail in at the furthest right part of the histogram. To do so is important to measure light with a spot meter, either in camera or with a handheld meter, and overexpose them by approximately 2 f-stops, depending on the sensor. Later in postproduction it is possible to change that exposure to our creative needs but maintaining the best SNR (signal to noise ratio) or quality our sensor is capable to obtain. If you are using positive film the way of exposure is approximately the same but when using negative film we will measure for the shadows and underexpose depending on the film.

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