Theatrical lighting can present the photographer with huge challenges. A dramatic lighting plot can typically feature strong colours and highly contrasting areas of localised light. Sometimes the action will take place in areas of subdued lighting or feature highly animated characters. All of these conspire against the camera’s metering system to the point where the photographer has to make decisions that are outside the cameras designed remit.
Camera metering systems are designed to deal with “average” scenes. These are typically situations where the average of colour and light amount to a mid grey. The job of a lighting designer on the other hand is to produce a spectacle that is far from average. The human eye has an enormous capacity to deal with differing levels of light and white balance within a scene, much more than most cameras. The challenge to the photographer is to make decisions about exposure and white balance that best reflects what the eye sees on the stage.
Faced with this challenge, the theatrical photographer has a couple of options. The first is to allow the camera to make decisions about exposure and white balance. This can work in some situations, but not others. The alternative is to take control and override the camera’s automatic settings and choose the aperture and shutter speed yourself.
Allowing the camera to make all the decisions can work in some circumstances where lighting is less dramatic. However, if you’re faced with bright and dark areas on the stage you may need to change metering modes.
The default metering mode for most cameras is evaluative metering. In this mode, light is measured across the picture and a calculation made. If you’re faced with areas of bright and dark, for instance a performer in a tight spotlight against a dimly lit background, you can end up with a picture where the performer is overexposed. For situations such as this you could select centre-weighted or spot metering. Unlike evaluative metering, centre-weighted metering places a greater emphasis on the levels of light towards the centre of the picture. Spot metering measures only the light from a particular part in the picture, which can be selected manually. If your subject is in the center of the picture then centre-weighted metering may be the best option. However, if you’re placing the subject elsewhere in the frame, you might want to use spot metering. In many dSLR cameras you can select a combined focal and metering point, so that the camera will both focus on and measure light from a point you select in the viewfinder.
Another approach might be to use EV compensation. If the circumstances allow you can take a test picture and then make subsequent exposures brighter or darker by dialing in EV (Exposure Value) compensation. This simply takes the exposure calculated by the camera and then over or under-exposes based on the value you dial in. Depending on which mode you’re shooting in, this can result in an exposure that uses a larger or smaller aperture than the camera calculates; or a longer or shorter shutter speed.
A further option is to take complete control and set the aperture and shutter speed manually, using the camera’s metering system as a guide. As well as the metering modes discussed above, you can use a zoom lens with evaluative metering to zoom in on a given area to get a meter reading and then set the exposure, before pulling out to frame the photo. This is often my personal preference.
Whatever method you choose, remember that there is no right or wrong way. You should use the method that suits you best and gives the results you’re looking for. Some productions and lighting plots can be more challenging than others so you should feel free to adapt methods to the circumstances you’re faced with.