When you point your camera at a subject, it needs a way of measuring the light reflecting from that subject. This measuring of the reflectance of light is what determines the exposure for a photo.
Whatever shooting mode you’re using, the camera (or you, if you’re shooting in manual mode) needs to know how much light there is to set the exposure (shutter speed and aperture) correctly.
This tool for measuring light reflectance is called the light meter, and understanding how it works is crucial to your ability to get correctly exposed images.
Most modern cameras use TTL metering, which stands for through the lens, and this means that your camera looks at the light coming through your lens as it evaluates the brightness of the scene.
There are also handheld light meters and another lesser-used mode of measuring light called ‘incident light’ measurement.
In this guide, Jo Plumridge is going to explain precisely how the camera meter works so that you can feel confident shooting at all times.
Here’s what she covers:
- How does your camera measure light?
- Reflected versus incident light.
- Understanding metering modes.
- How to view and understand the metering scale (exposure meter).
Certain types of scenes can fool a light meter, and that is the purpose of this guide — to make you aware and help you understand how a location might affect the camera meter.