Minolta Color Meter

Overview

The Minolta Color Meter is a series of portable color temperature and color correction measuring devices from the Japanese manufacturer Minolta (now Konica Minolta). Unlike a classic light meter, which only measures the amount of light, a Color Meter measures the color of the incident light and determines the color temperature and recommended correction filters from it. In film and photography practice, the device is used to match mixed or unknown light sources on set to a defined white point.

Known models include the Color Meter II, the Color Meter III, and the top-of-the-line model Color Meter IIIF, which can also measure flash light (the "F" stands for Flash). All models are no longer in production today and are mainly traded on the used market.

Principle of Operation

The measuring device has a sensor head with three silicon photocells, each responding to red, green, and blue. From the ratio of these three measured values, the device calculates the color temperature of the light and suggests the necessary filtering for correction. The output includes:

• LB value (Light Balancing) – for shifting the color temperature along the blue/amber axis
• CC value (Color Compensation) – for correcting green/magenta casts
• Color temperature in Kelvin

The Kelvin value output is the so-called photographic color temperature (based on the blue/red ratio), which in practice is treated like correlated color temperature, but differs slightly from it physically. The filter recommendations refer to a selected target white point. Three film types can be selected as references: Daylight (5500 K), Type A Tungsten (3400 K), and Type B Tungsten (3200 K). The IIIF model stores correction values in multiple memory channels and can measure continuous light, flash, or a mixture of both.

Technical Data (Color Meter IIIF)

Use on Set

On set, the Color Meter is used to match light sources to each other and to the sensor or film white point. Typical applications include identifying color casts in fluorescent or HMI sources, balancing daylight and artificial light in mixed lighting situations, and selecting the appropriate conversion or correction gel for lights and windows. The output LB/CC values can be translated into specific filters (e.g., Wratten or gel conversion filters). Since modern digital cameras perform white balance electronically, the device is used less frequently today than in film days, but it remains a useful reference tool in cinematography for the precise assessment of light color.