The mismatch of spectral responsivity to the CIE V(lambda) function, i. e., the f1' index, is the most critical characteristic of photometers and tristimulus colorimeters. The f1' value varies with measurement conditions, which is often omitted in the f1' evaluation. We investigated the variations of the f1' value with different measurement conditions such as angle of incidence, spatial uniformity, and ambient temperature, by measuring eight high-grade commercial photometer heads from four manufacturers. The f1' values measured by three different facilities as well as manufacturers' data were compared. The results indicate that f1' value can change considerably under different measurement conditions depending on the design of photometers.
The CIE Expert Symposium 2008 on Advances in Photometry and Colorimetry, Turin, Italy
, SHEN, H.
, Zong, Y.
and Ohno, Y.
f1’ EVALUATION AND MEASUREMENT COMPARISON, The CIE Expert Symposium 2008 on Advances in Photometry and Colorimetry, Turin, Italy, Turin, 1, IT, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=842554
(Accessed November 28, 2023)