Spectrophotometer-FAQs

A spectrophotometer is a color-measuring instrument used across all industries to compare the color of a sample with a standard, capture accurate L*A*B values, and calculate ΔE to ensure consistent and accurate color quality for any material – plastics, paints, textiles, prints, food products, or liquids.

• A Light source emits visible light which has different wavelengths (ROYGBIV).
• Light passes through an entrance slit and falls on a dispersive element which separates it into component wavelengths.
• A monochromator selects a specific wavelength of light at every 10 nm interval and directs it onto the sample.
• The sample reflects and absorbs some portions of the light.
• A detector measures the intensity of the reflected light, allowing for the analysis of the sample’s color.

Spectrophotometers mainly use two measurement geometries:

• 45°/0° geometry – This gives the overall appearance exactly as our eyes see the sample. It excludes gloss, making it best suited for matte surfaces.
• D/8° integrating sphere geometry – This has SCI and SCE modes, allowing you to see both the true color (SCI) and the visual appearance including gloss (SCE). It works well for matte, glossy, textured, and uneven surfaces.

Which geometry should you choose?

• If you deal only with matte materials, 45°/0° is the best choice.
• Otherwise, D/8° is the more flexible option, as you can switch between SCI and SCE based on whether the surface is matte or glossy.

Portable (handheld) 

• Light weight and easy to carry for on-the-go use
• Ideal for fieldwork and remote locations.
• Perform measurements at the site itself.
• Great for quick and accurate color quality checks.

Benchtop 

• Designed mainly for stationary use in labs and quality control departments
• Offers accurate and stable color measurements
• Supports a wide range of color analysis
• Perfect for detailed and complex color analysis

Manual:

• Human error is more likely in manual processes
• Manual methods struggle to detect slight variations in color
• Lighting conditions affect color perception, which naked eye can’t detect

Spectrophotometer:

• Provides precise and repeatable color readings
• Detects even minor color deviations
• Spectrophotometers use different light sources for accurate, consistent measurements

• SCI (Specular Component Included) – Measures total color including surface gloss, which helps detect subtle color differences. It works well for matte, glossy, textured, and uneven surfaces.
• SCE (Specular Component Excluded) – Measures color while excluding surface gloss. It is best suited for matte surfaces.

A colorimeter and a spectrophotometer are both used for color measurement, but they differ in accuracy, capability, and applications.

Colorimeter

• Measures color based on RGB filters
• Gives quick color readings but with limited accuracy.
• Cannot show full spectral data or detailed appearance differences.
• Suitable for basic color checks where high precision is not critical.

Spectrophotometer

• Measures full spectral reflectance and provides detailed Lab values, ΔE, and spectral curves.
• Much more accurate and consistent, especially for complex colors and textured/glossy materials.
• Can compare sample vs standard, evaluate gloss influence (SCI/SCE), and provide precise color control.

D65

Most widely used illuminant, simulating average daylight

A

Represents a tungsten-filament lamp simulating yellowish indoor lighting conditions

F1, F2, F7, and F11

Fluorescent light sources, each representing different types of fluorescent lighting

• F1 (Daylight Fluorescent) mimics daylight-like conditions
  
• F2 (Cool White Fluorescent) commonly used in retail environments
  
• F7 (Broadband Fluorescent) offers a more neutral, balanced spectrum
  
• F11 (Narrow Band Fluorescent) is similar to F2 and often used in commercial settings where cool white lighting is prevalent

• Aperture is the opening through which light interacts with the sample before measurement
• Ensures precise color measurement across varied sample sizes and textures
• Aperture sizes can vary, typically ranging from small (4mm) to large (up to 25mm)
• (4mm): Ideal for fine details, small areas, minimizes surface imperfections
• (25mm): Best for uniform surfaces; averages color over a larger area, reducing minor inconsistencies