45° Sparkle Measurement
The Effect Finish module quantifies how visible and intense sparkle effects appear when an effect coating is viewed at a 45/0 geometry, i.e. illuminated at 45° and observed close to the normal. At this angle, sparkle is often more pronounced and directional, so these parameters are particularly useful for matching appearance in real-world viewing conditions on automotive and other effect-coated parts.
SpR (45°), SpG (45°), SpB (45°)
- SpR (45°): Sparkle Red 45° is the red-channel intensity of sparkle elements seen at 45°, indicating how strong the red component of the sparkle appears at this off‑specular angle.
- SpG (45°): Sparkle Green 45° is the green-channel intensity of sparkle elements seen at 45°, describing the green contribution to the sparkle impression.
- SpB (45°): Sparkle Blue 45° is the blue-channel intensity of sparkle elements seen at 45°, describing the blue component of the sparkle effect.
Density (45°)
- Density (45°): Sparkle Density 45° is the number of visible sparkle points per 100 mm² at 45°, describing how densely the surface appears filled with sparkle elements when viewed from this angle.
- Higher Density (45°) values indicate a busier, more active sparkle field, whereas lower values correspond to a sparser, more subtle effect.
Area (45°)
- Area (45°): Sparkle Area 45° is the average size of detected sparkle elements at 45°, representing the typical image area covered by individual sparkles.
- Larger Area (45°) values suggest coarser, more prominent sparkle particles, while smaller values correspond to fine, pin‑point sparkle.
Brightness (45°)
- Brightness (45°): Sparkle Brightness 45° is the average luminance of the sparkle points at 45°.
- Higher Brightness (45°) values mean that individual sparkle points are more intense.
Visibility (45°)
- Visibility (45°): Sparkle Visibility 45° is the average perceived brightness of sparkle elements at 45°, taking into account their visibility and the background colour of the material.
- This parameter is designed to correlate with human perception of how noticeable the sparkle effect is at 45°, combining contributions from density, area and brightness against the underlying coating colour.
| Parameter group | Parameter | Unit | Description |
|---|---|---|---|
| 45° sparkle metrics | SpR (45°) | Intensity (0–255) | Red‑channel sparkle intensity at 45°, indicating how strong the red component of the sparkle appears at this off‑specular angle. [3] |
| SpG (45°) | Intensity (0–255) | Green‑channel sparkle intensity at 45°, describing the green contribution to the sparkle impression. [3] | |
| SpB (45°) | Intensity (0–255) | Blue‑channel sparkle intensity at 45°, describing the blue component of the sparkle effect. [3] | |
| Density (45°) | 1/100 mm² | Number of visible sparkle points per 100 mm² at 45°, describing how densely the surface appears filled with sparkle elements. [3] | |
| Area (45°) | mm² | Average size of detected sparkle elements at 45°, representing the typical image area covered by individual sparkles. [3] | |
| Brightness (45°) | AU* | Average luminance of the sparkle points at 45°, indicating how bright each sparkle appears relative to the surrounding surface. [3] | |
| Visibility (45°) | AU* | Average perceived brightness of sparkle elements at 45°, taking into account their visibility and the background colour of the material. [3] |
*AU = arbitrary (instrument) units.