Sharpness (TAMS High Gloss)

Sharpness (S) – High gloss mode

Definition

Sharpness (S) is a perception‑based index that quantifies how accurately images are reflected in a high gloss surface. It describes how crisp or blurred the reflected pattern appears, linking directly to visual impressions of haze and clarity.

Unit and range

Sharpness is expressed in percent (%), from 0% (very low sharpness, heavily blurred reflection) to 100% (perfect image reproduction with no visible blur). On real automotive clear‑coat surfaces, values typically sit between these extremes depending on coating system and process settings.

Measurement conditions

Sharpness is available in High Gloss Mode when the surface type is set to C‑Coat and a high‑gloss algorithm such as CC‑TAMS‑STD is selected. Measurements should be taken on clean, defect‑free areas with good contact between the TAMS measuring base and the surface.

Meaning at different viewing distances

Sharpness characterises the surface across two practical viewing conditions:

  • At close distance (approximately <0.5 m), Sharpness indicates how well the surface reproduces fine details of the reflected pattern, such as edges and small features.
  • At showroom viewing distance (around 1.5 m), Sharpness is closely related to haze and clarity, describing how much the reflected image appears “milky” or washed out versus clean and transparent.

High Sharpness means that reflections remain well defined at both distances; low Sharpness indicates that fine detail is lost and the surface appears hazy or smeared.

Relationship to other parameters and indices

Sharpness works together with other TAMS parameters to describe overall appearance:

  • With Contrast (C), it defines how vivid and detailed the reflection looks, especially on dark, high‑contrast colours.
  • With Waviness (W) and Dimension (D), it helps separate blur caused by haze (sharpness‑related) from distortion caused by large‑scale texture or orange peel.
  • A rescaled internal metric, Sharpness‑Q (Sq), uses Sharpness and Contrast as inputs to improve the perceptual weighting in the Quality (Q) index; Sq itself is not shown on the instrument but is used in the Quality calculation.

Typical interpretation

  • S > 80%: Very crisp reflections with minimal haze, typical of high‑end clear‑coat finishes and well‑polished surfaces.
  • S ≈ 50–80%: Poor sharpness for many production finishes.
  • S < 50%: Obvious haze and loss of detail in reflections; surfaces often appear “soft” or dull, signalling coating, curing or polishing issues that reduce perceived quality.

In practice, Sharpness can be trended alongside Quality (Q) and Waviness (W) to diagnose whether loss of appearance quality is driven mainly by haze/clarity (low S) or by texture/orange peel (high W), guiding targeted adjustments to paint application, curing or polishing processes.