What Is a Lux Meter?
- Lux meters are most commonly used by photographers and cinematographers to determine the intensity of the light falling on a photographic subject. The photographer uses the lux reading to determine the camera's aperture and exposure settings.
- There are two main types of lux meters: reflected-light meters and incident-light meters. Reflected-light meters are situated near or in the camera itself and measure the intensity of the light reflected from the subject to the camera. Incident-light meters are situated as close to the subject as possible and measure the intensity of the light falling on the subject.
- These are commonly installed in consumer products like camcorders or point-and-shoot cameras. They work well for scenes in which light is relatively evenly distributed, since the readings they take are of the general light intensity in the scene. Scenes containing objects whose brightness varies greatly (such as sunsets) will generally not be properly exposed when using readings from reflected-light meters. Nevertheless, reflected-light meters are useful when shooting subjects the photographer is not at leisure to pose and measure.
- These are always separate devices and generally used by serious film photographers. During measurement, they are held in front of the subject with their light receptor facing the camera. A photographer may measure the intensity of the light falling on several subjects in a scene before deciding how to set the camera.
- While incident-light meters are essential for professional film photography, they are considerably less necessary in digital photography. Because it is easy and free to take a test shot with a digital camera, one that can be immediately examined, a digital photographer can use a camera's reflected-light meter for a base reading, make a test shot and adjust the exposure based on the results.
