SIST ISO 10157:2011 PDF

Overview

ISO 10157:1991 specifies requirements for photoelectric flash exposure meters used in photography. The standard covers meters that measure the time integral of luminance or illuminance produced by brief light sources (electronic flash), and it defines measurement units, calibration procedures, environmental and mechanical tests, and performance characteristics required for reliable flash exposure metering.

Key topics and technical requirements

• Measurement type and units
  • Time integral of luminance (recommended unit: candela·seconds per m²) or illuminance (lux·seconds).
  • Aperture and flash-duration ranges must be indicated (e.g., measurement possible at ISO 100/21°).
• Gate time and storage time
  • Gate time: interval during which the meter integrates flash + continuous light; if a single fixed gate is used it must be at least 0.00781 s.
  • Storage time: period after gate during which the indicated value remains readable and must be specified on the meter or in documentation.
• Calibration and spectral response
  • Calibration/checking uses known exposures compared with the meter indication at the meter’s acceptance point.
  • Calibration light-source correlated colour temperature: 5500 K ± 200 K.
  • Spectral response must be continuous across the visible spectrum (380–780 nm); response due to wavelengths >700 nm or