ISO 9336-1:2010

Overview

ISO 9336-1:2010 - "Optics and photonics - Optical transfer function - Application - Part 1: Interchangeable lenses for 35 mm still cameras" - specifies a standardized method for testing interchangeable 35 mm camera lenses (image format 24 mm × 36 mm) to obtain valid optical transfer function (OTF) measurements. The part defines the required imaging states, test-bench configuration, spectral conditions and measurement parameters for Modulation Transfer Function (MTF) and, optionally, Phase Transfer Function (PTF). Special macro lenses designed exclusively for magnified imaging (e.g., dedicated 1:1 macro types) are excluded.

Key topics and requirements

• Scope and exclusions: Applies to interchangeable lenses for 24×36 mm format; excludes dedicated macro-only lenses.
• Imaging states: Specifies image heights to measure (0, 0.3h′, 0.5h′, 0.7h′, 0.85h′ where h′ half-diagonal = 21.6 mm) and azimuth/angle positions (0°, 90°, 180°, 270° or diagonal alternatives).
• OTF measurements: MTF is mandatory, PTF is optional; spatial frequencies for measurement and presentation are defined (recommended measurement frequencies 10, 20, 40 mm⁻¹; presentation frequencies up to 50 mm⁻¹; digital presentation: ten equidistant frequencies from 5 to 50 mm⁻¹).
• Test bench configuration: Measurements may be at object-to-lens infinite conjugate or finite distances (including minimum focus). The standard recommends repeat tests at finite distances.
• Spectral/light source conditions: Spectral domain at least 380–670 nm; recommended tungsten-halogen source at (3200 ± 200) K with a blue-reducing filter and an S‑20 photocathode photomultiplier as analyser. (Example filter: Schott BG 38, 1 mm - provided as market example, not an endorsement.)
• Aperture settings: Full-open aperture and an intermediate (“average”) aperture defined (e.g., average f/5.6 if full-open < f/4, otherwise f/8); guidance for selecting a second maximum aperture (~1.4× full-open f-number or nearest available setting).
• Accuracy & intercomparability: Requires evaluation of global accuracy, intra-lab repeatability and inter-lab reproducibility using known reference lenses. Reports must include measurement plane position and estimated measurement uncertainty.

Applications and users

• Lens manufacturers and optical designers - for product verification, design validation and quality control.
• Independent test laboratories and metrology labs - to produce comparable MTF/PTF data.
• Camera manufacturers and R&D teams - for system-level imaging performance assessment.
• Photographic equipment reviewers and standards bodies - to report standardized lens performance metrics.

Keywords: ISO 9336-1:2010, optical transfer function, OTF, MTF, PTF, interchangeable lenses, 35 mm still cameras, lens testing, imaging test method.

Related standards

• ISO 9334 - OTF definitions and mathematical relationships.
• ISO 9335:1995 - OTF principles and measurement procedures.
• ISO 9336 (other parts) - Part 3 covers telescopic systems.