The Complete Handbook of Light Meter Accessories

Chapter 1: Understanding Light Meter Accessories

What Light Meter Accessories Actually Are

A light meter accessory is any component that modifies how a light meter gathers, transmits, or interprets light before it reaches the sensing cell. This is not the meter itself, and it is not the battery that powers it. An accessory sits between the scene you are measuring and the meter's electronics, changing the meter's field of view, its sensitivity to specific angles of incidence, the spectrum of light it sees, or the way it communicates with other equipment. While these parts are often small and inexpensive relative to the meter itself, they are not cosmetic additions. They are functional optics and mechanics that fundamentally shape the data your meter reports. A light meter reading is only as useful as the integrity of the light path leading to it; every dome, disc, lens, adapter, and trigger in that path is a potential point of fidelity or failure.

Consider the most ubiquitous accessory: the incident light dome. Most handheld meters, such as the Sekonic L-358 or the Gossen Digisky, come with a white or milky hemispherical dome that can be slid over the sensor. This dome, sometimes called a lumisphere, is a diffuser. It collects light from a 180-degree field and integrates it. When you point the meter at the camera position and the dome toward the key light, you are not measuring the light bouncing off the subject. You are measuring the light falling on the subject from