Toward a more accurate and extensible colorimetry. Part IV. Visual experiments with bright fields and both 10° and 1.3° field sizes
✍ Scribed by William A. Thornton
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 204 KB
- Volume
- 22
- Category
- Article
- ISSN
- 0361-2317
No coin nor oath required. For personal study only.
✦ Synopsis
Bright strongly metameric visually matching coupled by quartz light-pipe to the spectroradiometer, set pairs of white lights are studied. Generally, one member at 7-nm bandwidth at half-height. The resulting SPDs are of the pair is a constant broadband reference white, in 500-point, 1-nm interval, 250-749 nm, in units of 10 09 accordance with the Maxwell method. Spectral composiwatts/cm 2 -nm. They are corrected against the SPD of a tions of the other member are chosen from eight types quartz-halogen reference lamp at 3170 K, traceable to found in Parts I, II, and III to lead to tristimulus errors, NIST, which provides 167 f L (570 candelas/m 2 ) from over a large range of magnitude, by the 1964 CIE Stana perfect diffuser at 50 cm. Our earlier measurements dard Observer. Field luminance has been tripled over utilized 10Њ visual fields, and brightnesses equivalent to that of the earlier work to the order of 100 cd/m 2 , the no more than 10-12 f L (35-40 cd/m 2 ). Large errors by range of typical industrial color-matching. Experiments the 1964 CIE Standard Observer in computed tristimulus with visual fields of 1.3Њ have been added. Tristimulus values of the visually matching lights in top and bottom errors in computations by the appropriate CIE Standard fields were documented. Observer, at the higher brightness levels, and at visual The purpose of this Part IV is to extend measurements field sizes of both 10Њ and 1.3Њ, are as large as those of visual matches, at the colorimeter-spectroradiometer, found in the earlier work with dimmer 10Њ fields. ᭧ 1997 of pairs of highly metameric lights. Brighter fields, and