Contrast (TAMS High Gloss)

Contrast (C) – High gloss mode

Definition

Contrast (C) is a colour‑dependent index that quantifies the difference between bright highlights and dark areas in the reflected image on a high gloss surface. It describes how “strong” the reflection appears and captures the influence of basecoat colour on perceived appearance.

Unit and range

Contrast is expressed in percent (%):

  • White and light metallic surfaces show low contrast (<30%)).
  • Deep black can approach 100% contrast.

Measurement conditions

Contrast 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. It is calculated from the reflected pattern images captured by TAMS.

Colour dependence and visual meaning

Contrast is directly linked to the colour and optical density of the surface:

  • On dark, high‑contrast colours (for example black), reflections exhibit a large intensity range between bright and dark regions, so texture, haze and DOI defects are much more visible.
  • On light or metallic colours with low contrast, the same physical orange peel or haze can be far less noticeable to the observer.

Because of this, Contrast acts as a bridge between colour and texture. It explains why strict texture limits that are appropriate for black cars may be unnecessarily tight for silver, and why controlling only colour‑blind metrics (such as waviness or DOI alone).

Relationship to other TAMS parameters and indices

Contrast plays a central role in the perception‑based metrics used in High Gloss Mode:

  • With Sharpness (S), it defines how vivid and detailed the reflection looks – high C and high S give deep, crisp images, while low C or low S make the surface appear flat or hazy.
  • It influences the Quality (Q) index, helping Q respond correctly to differences between dark and light colours by reflecting the real visual impact on the customer.
  • Through its colour dependence, it supports more realistic Harmony (H) assessments across different colours, ensuring that panel‑to‑panel matching is judged in a way that aligns with human perception.

Typical interpretation

  • C > 70%: High‑impact, deep colour (e.g. solid black or dark shades). Texture, orange peel and haze are very visible; tight control of Sharpness, Waviness and Harmony is usually required.
  • C ≈ 30–70%: Medium contrast colours (mid‑tones, some saturated colours). Texture and haze are visible but less critical than on deep black.
  • C < 30%: Low‑contrast finishes (whites, light metallics, pastel shades). The same texture level that is unacceptable on black may be visually acceptable here.