Answer
May 21, 2025 - 12:00 PM
In the case of general fluorescent lights, almost all the figures of R9 in CRI show negative. Ri is the index number which is obtained with calculation, not percentage. Therefore, these index numbers are below 100, sometimes negative. Please refer to the following formula.Ri = 100-4.6 * delta Ei *delta Ei (i = 1 to 9) is the difference of response from the standard color patch when lighted by your light source and standard light.
