Fig. 1. Principle of thin film interference

Fig. 2. Twelve geometric measurement conditions of X-rite MA-T12 multi angle spectrophotometer. (a) 45° receiving angle; (b) 15° receiving angle

Fig. 3. R1 angle-resolved spectrum device and measurement conditions. (a) Measurement device; (b) measurement conditions

Fig. 4. Photographing the actual results. (a) Camera shooting conditions; (b) relative spectral power distribution of light sources

Fig. 5. Microstructures of different samples and visual appearance at difference angles

Fig. 6. Spectral distributions of different samples using X-rite MA-T12

Fig. 7. a10*b10* chromaticity values at different measurement conditions. (a) 45° receiving angle; (a) 15° receiving angle; (c) 15° specular angle

Fig. 8. Diagram of the measurement condition of (α,β)

Fig. 9. Distributions of a10*b10*chromaticity values at different (α,β) measurement conditions

Fig. 10. Relationship between angle of β andCnormal*