Ultra Dark Mode was developed to overcome the unique challenges of measuring extremely dark, matte, or textured materials across industries such as automotive coatings, plastics, textiles, chemicals, and foods. By optimizing illumination, detector sensitivity, and signal processing, Ultra Dark Mode enables accurate color evaluation of materials containing carbon black, metallic pigments, or low-gloss surfaces. This ensures manufacturers can monitor production quality, maintain color consistency across global supply chains, and validate visual uniformity between laboratory and production environments.

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Description

The HunterLab Agera L2 Ultra Dark Mode is a specialized operating mode designed to deliver superior color accuracy, repeatability, and stability when measuring ultra-low reflectance samples—typically those below 15% reflectance. These materials, which include carbon-black-based coatings, dark plastics, powders, textiles, and foods, often present unique optical challenges that exceed the limits of standard spectrophotometric systems.

Ultra Dark Mode combines optimized illumination control, enhanced detector sensitivity, and advanced signal processing algorithms to maximize the signal-to-noise ratio (SNR) in dark regions of the reflectance spectrum. The result is true-to-appearance, visually correlated color data that allows manufacturers to measure, monitor, and manage the darkest materials with confidence and consistency.

Purpose

Color uniformity in very dark products is critical across industries—from ensuring batch-to-batch consistency in automotive coatings and black masterbatches, to maintaining the aesthetic quality of dark roasted coffee or cocoa powders. Traditional spectrophotometers often struggle in this range, as stray light, detector noise, and surface irregularities can distort measurements.

The purpose of Ultra Dark Mode is to eliminate these sources of error, enabling accurate, reproducible color data that supports:

• Process optimization and batch validation
• Visual correlation between laboratory and production environments
• Global quality standardization across supply chains
• Regulatory compliance and product traceability

Why Ultra Dark Samples Are Challenging

Ultra-dark materials reflect only a small fraction of incident light—often less than one-fifth of what a mid-tone sample reflects. This creates multiple challenges:

• Low Signal Strength: Minimal reflected light leads to higher susceptibility to electronic noise.
• Stray Light Sensitivity: Even small amounts of scattered or internal reflection can disproportionately affect results.
• Texture and Gloss Variability: Matte, semi-gloss, or uneven surfaces produce directional reflections that distort average readings.
• Detector Nonlinearity: Standard detectors may lose precision in the lower reflectance region, causing unstable ΔE values.

Agera L2’s Ultra Dark Mode directly addresses these issues by refining illumination intensity, optimizing detector gain, and employing algorithmic compensation for noise and scatter effects.

Technical Overview of Ultra Dark Mode Operation

Ultra Dark Mode integrates several hardware and software-level optimizations within the Agera L2 platform:

• Dynamic Illumination Control – The LED illumination system automatically adjusts to deliver stable, uniform light intensity at low reflectance levels without saturating the detector
• Enhanced Detector Gain & Filtering – The optical detector operates in a high-sensitivity range with digital noise filtering, preserving accurate signal response in the near-zero reflectance domain
• Stray Light Reduction Optics – Internal baffling and coated optical surfaces minimize stray reflections that can skew readings on black or textured samples
• Advanced Averaging Algorithm – Multiple readings per measurement cycle are combined statistically to reduce variability and deliver the true mean reflectance
• Visual Correlation Assurance – 0° illumination / 45° circumferential viewing geometry ensures the data aligns with human visual perception, even for textured, matte, or semi-gloss dark surfaces.
• Provides Ultra Dark ISO Compliant Industry Standard Indices:  Blackness (My, Mc, dM), Greyness (Gy, Gc, dG).

ISO Conformance for Extremely Dark Samples

When measuring extremely dark, near-black, or low-reflectance samples, conventional colorimetric scales (such as L*, a*, b*) often lack the sensitivity required to differentiate subtle appearance changes. To address this, ISO 18314-3: Analytical Colorimetry — Part 3: Special Indices and its predecessor DIN 55979 define standardized one-dimensional indices for evaluating blackness, jetness, undertone, and greyness. These indices are specifically designed for materials where reflectance approaches zero and small spectral variations significantly affect visual perception.

The HunterLab Agera L2, with Ultra Dark Mode, imaging-assisted measurement, and high signal-to-noise performance at low Y-values, is exceptionally well-suited for measuring these indices with stability and repeatability.

In the context of measuring very dark/black materials (e.g., carbon blacks, “jet-black” coatings), the Agera L2 conforms to, and reports, ISO 18314-3: Analytical Colorimetry — Part 3: Special Indices:

1. Blackness (Jetness) in ISO 18314-3

Scope & relevance:

• This standard provides methods for calculating special one‐dimensional indices such as blackness, jetness, and undertone (for example, Mₙ, Mₙₒ, dM) for dark or near‐black specimens.
• Applies especially where samples have very low reflectance (deep blacks) and conventional metrics (L*, a*, b*) may not adequately differentiate visual appearance.

Key indices defined in ISO 18314-3 include:

• Mₙ (or Mₙₒ): Hue‐independent blackness value.
• Mₙₒ (or Mₙ) sometimes called color‐dependent blackness (or jetness) value.
• dM (undertone): The difference between the colour‐dependent and the hue‐independent blackness values, indicating the bluish vs brownish undertone of black.

What dM Means

• The index dM = Mₙ – My, where:
  • My (or sometimes Mₙ) is the “blackness” value of the sample (sometimes derived from the Lippok-Lohmer/Jetness scale).
  • Mₙ (or Mc in some publications) is a combined value of blackness plus undertone. So: dM = Mc – My.

Interpretation:

• If dM < 0, the black has a brown-reddish undertone.
• If dM = 0, the black is considered achromatic (neutral).
• If dM > 0, the black has a bluish/“cool” undertone (often preferred for “piano black” or premium surfaces).

Purpose:

It gives manufacturers a quantitative way to assess the subtle color cast in a black film, coating, or granulate that otherwise reads as “black” in standard lightness or Y% scales.

When to use it:

• In coatings, plastics, pigments, or any application where the visual depth and undertone of black matter (e.g., automotive piano black finishes).
• When simply measuring “darkness” via L* or Y% is insufficient, and you need to quantify undertone and blackness in a standardized way.
• When inter‐lab comparability and deep‐black reproducibility are required.

2. Greyness in ISO 18314-3

Greyness (ISO 18314-3) is a standardized index that expresses the degree to which a sample is neutral (achromatic) rather than chromatic, independent of how light or dark it is. It complements blackness, jetness, and undertone for complete low-reflectance color characterization.

How Greyness Is Computed (Conceptual), the core idea:

• A perfect neutral gray has C* = 0.
• As C* increases (more color), the “greyness” decreases.
• As C* approaches zero, greyness increases.

A general form used in industry:

What Greyness Tells You

1. Evaluating whether a dark sample is truly “neutral black”

Even if two blacks have identical L* values, one may be slightly bluish or brownish.

• Jetness describes depth
• dM describes undertone
• Greyness describes the strength of chroma — how close it is to pure grey/black.

2. Characterizing low-chroma materials Such as:

• Charcoal plastics
• Graphite coatings
• Black rubber
• Low‐tint pigments
• Neutral grays in textiles or papers

3. Some very dark materials appear black but actually have measurable chroma:

• Plastics: neutral vs chromatic blacks; carbon black loading
• Automotive interiors: achieving neutral “soft black” surfaces
• Pigments & masterbatch: checking neutralization
• Textiles: consistent gray scale reproduction
• Coatings: low-chroma black and gray paints
• Electronics: “neutral matte graphite” housings
• Anywhere that customers demand neutral, not bluish/brownish, dark tones.

Why Greyness Matters in Dark-Sample Measurement

Extremely dark materials often look “black,” but, very small amounts of chroma (C* = 0.5–2.0) are visually obvious, especially under D65 or daylight booth lighting. Greyness helps quantify this subtle chromatic contamination.

For instruments like the Agera L2 (with Ultra Dark Mode), greyness becomes more measurable and stable because:

• Low stray light
• High Signal to Noise Ratio (SNR) in low Y% regions
• Precise calibrated D65 illumination
• Allows accurate chroma calculation even when C* is < 1.0.

ISO 18314-3 is the go‐to standard for describing the appearance of deep black and jet‐black surfaces (blackness & undertone). For QC of very dark finished materials (films, coatings, plastics, interiors) you will typically reference ISO 18314-3 metrics and ensure your instrument (like the Agera L2) is capable of the low‐reflectance precision required.

Compatibility with Agera Gen 1

Both the original Agera Gen 1 and Agera L2 performance and results remain fully aligned regardless of the Agera L2 mode used—ensuring continuity and perfect correlation with existing Agera measurements. The key benefit of Ultra-Dark Mode is that it gives a tighter, more consistent range, especially for these very low-reflectance samples. When Agera L2 identifies an ultra-dark sample, it will notify you. You can stay in standard mode for perfect historical correlation—or accept to activate Ultra Dark Mode. This preserves backward compatibility while offering improved precision when needed.

Applications and Industry Impact

  Industrial and Coating Applications:

• Automotive Coatings and Trim: Deep black paints, interior plastics, and matte coatings demand sub-ΔE0.5 precision. UDM ensures accurate characterization and global production consistency.
• Powder and Protective Coatings: Measures dark metallic or carbon-black-based coatings where gloss or surface texture can distort standard readings.
• Building and Construction Materials: Evaluates color stability of roofing granules, dark composites, and façade panels exposed to UV and environmental stress.

Plastics and Polymers:

• Black Masterbatches: Enables color matching and formulation verification in carbon-black and pigment-loaded pellets.
• Consumer Goods and Packaging: Maintains appearance uniformity in dark housings and enclosures across multiple suppliers.
• Automotive Interior Components: Ensures consistency across textured or molded surfaces with low reflectance values.

Textiles and Leather:

• Dyed Fabrics: Measures deep navy, charcoal, and black fabrics where gloss and weave affect visual tone.
• Synthetic and Natural Leathers: Provides stable readings on textured, matte, or embossed surfaces used in upholstery and apparel.

Paints, Inks, and Pigments:

• Decorative Paints: Evaluates deep-tone architectural paints for batch uniformity and long-term color retention.
• Camouflage and Industrial Coatings: Ensures precise matching of low-visibility and infrared-absorbing materials.
• Printing Inks: Monitors density and hue in black or dark-tinted inks for packaging and publication.

Chemicals, Minerals, and Powders:

• Carbon Black and Conductive Powders: Measures reflectance consistency in fine black particulates used in rubber, inks, and electrodes.
• Metal Oxides: Tracks production quality of iron oxide and manganese dioxide pigments used in coatings and catalysts.
• Battery Components: Quantifies reflectance of graphite, cathode, and anode materials for quality validation.

Pharmaceuticals and Cosmetics:

• Dark Tablets and Capsules: Ensures color uniformity in coatings containing iron oxides or natural pigments.
• Cosmetic Formulations: Enables precise tone control in mascaras, eyeliners, and pigmented creams where perceived depth defines quality.

Food and Beverage Applications:

• Cocoa, Coffee, and Tea Powders: Ultra Dark Mode quantifies roast and blend color to maintain sensory consistency.
• Chocolate and Confectionery: Ensures stable color and gloss balance in dark chocolate coatings and inclusions.
• Spices and Dry Mixes: Accurately measures paprika, black pepper, and activated carbon blends.
• Processed Meats and Proteins: Evaluates uniformity in dark-cured or roasted surfaces to ensure visual appeal and process repeatability.

Advantages of Ultra Dark Mode

• Enhanced Sensitivity: Accurate readings below 15% reflectance.
• Improved Repeatability: Reduces ΔE variability caused by detector noise and surface effects.
• Visual Correlation: 0°/45° circumferential geometry matches human perception of dark tones.
• Versatility: Performs reliably across powders, solids, and textured surfaces.
• Global Standardization: Enables consistent quality control across worldwide production and supplier networks.

Conclusion

The Agera L2 Ultra Dark Mode represents a major advancement in the instrumental color measurement of extremely low-reflectance materials. Agera L2 can report standardized blackness and jetness indices (My, Mc, dM) in alignment with ISO 18314-3 and DIN 55979. Greyness indices defined in ISO 18314-3 (G_Y, G_C, dG) can be used to characterize near-neutral dark and grey materials, complementing traditional L*, a*, b* analysis.

Different instrument manufacturers implement these indices with their own operating modes and thresholds, but the underlying definitions of My, Mc, dM, and G-values are standardized at ISO level. By combining refined optical design with intelligent signal control, HunterLab has created a tool capable of translating even the darkest, most complex visual surfaces into stable, traceable, and actionable data.

Whether ensuring brand consistency in automotive interiors, validating pigment concentration in masterbatches, or quantifying roast color in coffee or cocoa, Ultra Dark Mode extends the boundaries of color science—enabling manufacturers to achieve true visual correlation, global process alignment, and unparalleled confidence in dark color measurement.

To learn more about Agera L2, click this link: Agera L2

To learn more about Color and Color Science in industrial QC applications, click here: Fundamentals of Color and Appearance

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