The difference in light and shade and hue in the allowable range of normal chromatic aberration can be called "chromatic aberration". The traditional chromatic aberration evaluation method is to rely on the naked eye to observe directly, but due to the difference in observation conditions and the ability of human eyes to distinguish colors, there will be no unified standard for chromatic aberration evaluation. In order to make it easy for people to determine the color difference, a three-color excitation (stimulus) system based on the International Commission on Illumination (CIE) standard light source, standard and spectrum has been gradually formed and perfected. This method quantifies the color discrimination of vision and is characterized by tristimulus value XYZ. The user can use the colorimeter to determine the degree of color difference between the standard sample and the sample. The screen displays:
Large △L means white, small △L means black
△a large means reddish, △a small means greenish
Large △b means yellowish, small △b means blueish
△E represents the size of the total color difference
Different industries have different requirements for the color difference range of the product. At present, there is no uniform standard color difference range in the world. The main reason is that the manufacturer communicates with the customer to negotiate the color difference range of the product.
Allowable range of normal color difference:
1. 0-0.25△E: very small or no, it is an ideal match.
- 0.25-0.5△E: tiny, it is an acceptable match.
- 0.5 -1.0△E: small to medium, acceptable in some applications.
- 1.0 -2.0△E: Medium, acceptable in specific applications.
- 2.0-4.0△E: There is a gap, which is acceptable in specific applications.
- Above 4.0△E: Very large, unacceptable in most applications.