372 



COLOR AND LIGHTING 



Head 



Shield the hght fixture so it will not be a 

 severe glare spot such as is ordinarily found 

 there. 



General Summary 



The spectral quality or color of light in or- 

 dinary illuminants is relatively unimportant. 

 Only for threshold seeing is yellow slightly 

 better than other artificial illuminants. In 

 ordinary seeing situations which are supra- 

 liminal as in reading, one light is as good as 

 any other: tungsten filament, fluorescent, 

 mercury vapor, daylight. There is, how- 

 ever, a psychological objection to most fluo- 

 rescent hght because of its "harsh" and 

 "cold" appearance. 



Intensity of illumination has been con- 

 sidered in relation to visual acuity, size of 

 object to be discriminated, speed of vision, 

 brightness contrast, and efficiency of per- 

 formance. The trend of the data reveal that 

 visual efficiency of normal eyes increases 

 rapidly as illumination is increased from a 

 fraction of one up to 5 f.c, more slowly from 

 there up to about 10 f.c, and very slowly 

 from 10 to about 20 f.c. Thereafter, the 

 improvement in vision is slight when the 

 object to be discriminated is of moderate 

 size (3 to G minutes). When the object is 

 smaller, however, visual efficiency improves 

 by practical amounts up to 40 or 50 f.c. 

 And the greater the brightness contrast be- 

 tween object and background, the better the 

 visual efficiency. Certain visual functions 

 like visual acuity and speed of vision improve 

 by amounts that are insignificant in practical 

 situations up to more than 1000 f.c. for the 

 former and more than 100 f.c. for the latter. 



Visual efficiency and visual comfort are re- 

 duced by two factors of distribution: glare 

 from bright spots in the field of vision, and 

 marked brightness contrast between areas 

 in the field of vision. Illumination should 

 be as uniform as possible, and brightness con- 

 trasts between adjoining areas should be 

 small. A ratio of not more than three to 

 one between task and surrounds is best. To 



avoid glare, the surface brightness of light 

 fixtures should be as close to one candle per 

 square inch as possible. There should al- 

 ways be a coordination of intensity with 

 distribution in planning illumination. 



Painted walls, ceilings and furnishings 

 should be pleasing and should furnish reflect- 

 ing surfaces. Certain colors are preferred 

 over others, tints are preferred to saturated 

 colors, and tints are preferred in large rather 

 than small areas. The paint should be hght 

 enough to reflect a large portion of incident 

 light: ceilings 70 to 80 percent, bulkheads 

 40 to 50 percent, desk tops 30 to 40 percent 

 and floors 20 to 25 percent. Psychological 

 variety can be achieved by using contrasting 

 colors in adjoining areas and from room to 

 room. 



A light that enhances warmth and softness 

 of colored objects is desirable. Also, the 

 illumination should be one that does not 

 alter markedly the color of natural objects 

 as complexions and foods. Good decorative 

 schemes can be executed with a low bright- 

 ness contrast of around three to one. 



The research findings cited above find 

 many apphcations in the lighting and paint- 

 ing of submarines. A number of these are 

 hsted. 



Problems for Research 



There are a number of problems in lighting 

 and color in submarines that need further 

 research. Those which seem of greater im- 

 portance to the writer are listed below: 



1. The pleasingness of colors and color 

 combinations has been studied in the psycho- 

 logical laboratory, employing relatively 

 small areas of colored stimuh. No con- 

 trolled experimentation has been carried out 

 to discover the pleasingness of large areas 

 (walls of rooms) of color and color combina- 

 tions. This should be done. The present 

 use of colors is largely in terms of opinions of 

 artists and decorators. 



2. Light tints of colors and white paint 

 rapidly turn much darker in the submarine. 

 A paint laboratory should be given the task 



