Exposing to the "right"

There is an extremely interesting article about exposing to the right that was mentioned in the Lighting Essentials blog. The link is here. It is about how to maximize the signal/noise ratio by overexposing your photo and then adjusting the exposure back down. Effectively you are decreasing your effective ISO to do this. This requires that the photo is taken is RAW format and then adjusted in your RAW converter. However, the negative effects can also be present such as requiring longer exposure times, which can introduce blur into the photos.

The basic premise is that most of the detail data is included in the brightest part of the histogram. More specifically, that the brightest F-Stop of your available dynamic range (which may be 5 f-stops) may contain 1/2 of the entire data of the photo, yet some photos may not even have any of the exposure in that brightest f-stop.

When taking your photo, use the histogram to put as much of the picture data as far to the right as possible without clipping any of the data. Clipping data is the worst thing you can do to a photo, as once something is overexposed to the point where the highlights are blown out, the data can never be recovered. Anyway, the article explains the concept much better than I do.