Optical Testing Services

Scope

Optical testing covers the measurement of the optical properties of transparent, translucent, and opaque materials – including light transmission, haze, color, gloss, and refractive index – as well as the performance testing of optical components and systems.

Key measurements within the scope include:

• Haze and luminous transmittance – the percentage of transmitted light that is scattered by wide angles (haze) and the total light transmitted through the specimen (ASTM D1003); the primary clarity test for transparent plastics, films, and glazing
• Spectral transmittance and reflectance – measurement of light transmission and reflection as a function of wavelength, covering UV, visible, and near-IR; used for optical coatings, solar-control glass, and filters
• Color measurement – instrumental color characterization in CIELAB (Lab*) or other color spaces using a spectrophotometer or colorimeter; ΔE color difference between specimens or against a standard
• Gloss – the specular gloss of surfaces at defined angles (20°, 60°, 85°) per ASTM D523; used for paints, coatings, and finished surfaces
• Refractive index – the ratio of the speed of light in vacuum to that in the material; determined by refractometry for liquids and solids
• Optical density and absorbance – the degree to which a material absorbs light at defined wavelengths
• Precision optics testing – surface figure, wavefront error, focal length, MTF (modulation transfer function), and aberration for optical components and systems
• Applicable standards – ASTM D1003, D523, ASTM E308 (color), ISO 10110 (optics), and material- or product-specific optical standards

Applications

• Transparent plastics and films – haze and transmittance testing of packaging films, glazing sheets, polycarbonate, acrylic, and PET to verify optical clarity
• Architectural and automotive glazing – spectral transmittance, solar heat gain, visible light transmittance, and UV transmission of glass and glazing systems
• Optical coatings – characterizing antireflection, mirror, and filter coatings for transmittance and reflectance across the wavelength range
• Paint and coating gloss – measuring the gloss of painted and coated surfaces to confirm they meet the specified appearance
• Color quality control – confirming that materials, coatings, and products match a color target and that color differences between batches are within the acceptable tolerance
• Optical components – testing lenses, windows, and optical elements for refractive index, surface quality, wavefront, and transmission performance
• Weathering and aging assessment – measuring optical property changes (yellowing, haze increase, gloss loss, color change) in materials after weathering or accelerated aging

Benefits

• Quantifies how a material will look and perform optically – instrumental optical testing replaces subjective visual judgment with defined, comparable numerical values for clarity, color, and gloss
• Catches haze and clarity defects early – transmittance and haze testing at incoming inspection or production catches defects that would be visible to the end user
• Supports color control across batches and suppliers – CIELAB color measurement gives a defined tolerance window for color, enabling consistent color across production runs and suppliers
• Traces optical property changes after aging – comparing optical properties before and after weathering, thermal aging, or UV exposure reveals how the material degrades optically, supporting product development and shelf-life decisions
• Covers both bulk materials and precision optics – the same optical testing capability addresses commodity film and glazing properties and the precision requirements of optical components
• Standardized and comparable – ASTM and ISO methods provide a consistent basis for specification, acceptance, and comparison