Camera light meters are highly useful when taking photographs since they help you figure out the ideal exposure by measuring the amount of light in the scene. Most modern cameras have built-in light meters which are usually sufficient in determining proper exposure. But there will be instances when in-camera light meters can become unreliable and that’s when a hand-held light meter is better suited for the job.
Camera light meters work by reading the light levels from the subject or scene and determining one brightness value, and then using it to approximate the ideal shutter speed and aperture number. The brightness value used is a medium gray tone, since the meter always attempts to get the average of the various tones in the scene.
Reflected Light and Incident Light Reading
All in-camera light meters measure light which bounces off the subject or scene, this is also known as “reflected light”. In-camera light meters will do fine when the scene has various tones but if it is predominantly dark (such as night scenes) or mostly white (such as snow scenes), the camera’s light meter will compensate by suggesting settings that will end up giving the dark or bright scenes a grayish tone instead.
Hand-held light meters come in handy especially in such cases. Aside from being able to measure reflected light, they can also be used to measure incident light, which is the light falling on the subject or scene. The subject’s reflective quality is not factored in the computation. This gives a more accurate reading and will help ensure that the dark areas and the light areas keep their tones.
Various Hand-Held Light Meters
Hand-held light meters have been around for a long time. In the days of film, analog light meters with their dials and needles were used to take light readings. The film speed was set beforehand, then the camera light meter was held near the subject with the dome-like diffuser facing the camera lens. A button or a dial would make the scale needle move as it read the light, and the device would provide the combinations of shutter speeds and aperture numbers for the exposure.
The more modern digital light meters work similarly with you setting the ISO and holding it up by the subject with the dome facing the camera lens. Analog and digital light meters vary in their features, with basic ones having one full stop settings, while the more advanced have the capacity to measure up to 1/10th stop and some can even do selective readings.
Both analog and digital camera light meters can provide accurate exposure readings so choosing a particular one is a matter of personal preference. Some like analog hand-held light meters over the digital models, saying the large needle is easier to read in bright light compared to an LCD screen. Also, they do not need batteries compared to digital light meters. On the other hand, others prefer digital light meters, claiming the analog light meter’s needle has to be viewed at a proper angle to get an accurate reading.