During the microphone check before this year’s Four Star Theater Awards show, the sound person asked my friend Holly to sing the loudest and quietest parts of her song. This allowed the engineer to set Holly’s microphone sensitivity to accommodate her dynamic range, from softest to loudest.
Camera sensors (and film) also have a specific dynamic range, from the brightest to the darkest data they can record. A digital camera sensor’s dynamic range compresses as one increases its sensitivity, and that’s why we usually try to shoot at the camera’s base ISO.
At my Nikon D300’s base ISO of 200, I get the broadest range of tones from light to dark. When I shoot theater and dance performances, I almost always have to ramp up to ISO 1600. Yet theatrical lighting tends to be dramatic – bright spotlights and harsh shadows. So, when I need the most dynamic range, I have the least available. That means I have to nail the exposure – there’s very little latitude.
Matrix metering can be fooled by bright or dark backgrounds, and center-weighted metering can be fooled by bright or dark costumes. Since I need the best exposure I can get for these high-contrast, high ISO situations, I use spot metering tied to the focus point, which I keep on the performer’s face. With experience, I’ve learned to dial in exposure compensation based on skin tone.
With this method, it may seem that I’m “exposing for the subject and letting the highlights and shadows fall where they may.” But usually, a spotlit face IS the highlight, so I’m really exposing for that and letting the shadows fall where they may.
Next time, I’ll show you what happens to a theater shoot when I have to stretch the camera’s dynamic range for unevenly lit groups.