Tables 3-8 show the distributions of the subjects’ assessments of the test room
appearance relative to the comparison room, and Figures 12-17 illustrate the mean data. It
can be seen that there are few instances of subjects reporting anything more than a slight
difference between the appearances of the two rooms. In fact, all of the mean values
correspond to fractional parts of a slight difference, and in many cases the reported
difference of appearance between the 3-band source and the comparison MR source was
less than the reported difference between the identical MR sources.
The brightness and clarity criteria attracted very few comments from the subjects. The
color appearance of the Escher print illuminated by the 3-band source attracted several
comments. Some subjects who rated the difference favorably described the test situation
as appearing “more white”, while others who rated it unfavorably criticized the nonuniformity
of color appearance. The blending of the colored light sources in the test
situation was imperfect, and this shortcoming was more evident when viewing the
achromatic print than when viewing the chromatic artworks.
The color appearance of the Mondrian illuminated by the 3-band source also attracted
comments. The colors were described as “less vivid” or “faded”, particularly the red
pigment. However, at the lower CCT there was some favorable comment that the blue
pigment appeared brighter, and also unfavorable comment that there was an overall
cooler appearance. These comments are understandable. Incandescent filament lighting enhances the apparent saturation of red colored surfaces, particularly at the lower CCT,
and reduces the apparent saturation of blue surface colors.
The appearance of the Renoir painting under the 3-band source attracted a variety of
both favorable and unfavorable comments. At the lower CCT, favorable assessments
(“colors seem to look better”) were matched by unfavorable assessments (colors “more
washed out”). At the higher CCT, flesh tones were criticized.
- Table 3.
- Subjective assesment ratings for:
Artwork - Escher
CCT - 2850K
| Criterior |
Light Source |
Rating |
Average Rating |
| -3 |
-2 |
-1 |
0 |
+1 |
+2 |
+3 |
| Brightness
| MR |
|
|
1 |
12 |
3 |
|
|
+0.12 |
| 3-B |
|
|
2 |
10 |
3 |
1 |
|
+0.19 |
| Clarity |
MR |
|
1 |
2 |
10 |
3 |
|
|
-0.06 |
| 3-B |
|
2 |
4 |
6 |
4 |
|
|
-0.25 |
| Overall color appearance |
MR |
|
|
1 |
10 |
5 |
|
|
+0.25 |
| 3-B |
|
|
1 |
8 |
5 |
2 |
|
+0.5 |
| Individual colors |
MR |
|
|
|
14 |
2 |
|
|
+0.12 |
| 3-B |
|
|
1 |
13 |
2 |
|
|
+0.06 |
| Naturalness |
MR |
|
|
2 |
12 |
1 |
|
|
0 |
| 3-B |
|
1 |
2 |
9 |
3 |
1 |
|
+0.06 |
