Luminance Thresholds For The Resolution Of Visual Detail During Dark Adaption

Item

Title
Luminance Thresholds For The Resolution Of Visual Detail During Dark Adaption
Date
1952
Index Abstract
Coming Soon
Photo Quality
Undetermined
Report Number
WADC TR 52-12
Creator
Brown, J. L.
Graham, C. H.
Leibowitz, H. W.
Ranken, H. B.
Corporate Author
Columbia Univ New York
Extent
19
Identifier
ADA075993
Access Rights
Unknown
Distribution Classification
1
DTIC Record Exists
Yes
Distribution Change Authority Correspondence
None
Abstract
Luminance thresholds for the visual resolution of various widths of alternating light and dark lines were determined at various times during dark adaptation. The finest gratings, representing high degrees of visual acuity, show only a single cone curve that drops from a high luminance threshold during the first moments of dark adaptation to a final steady level that is reached after about 7 to 10 minutes in the dark. Coarse gratings produce a duplex curve that shows an initial cone portion and a delayed rod portion. Visual acuity is a parameter that sets the position of a given curve on the log threshold axis. The higher the degree of resolution required, the higher the dark adaptation threshold. At a constant grating luminance, visual acuity rises rapidly to a maximum during dark adaptation; the higher the luminance, the earlier and more rapid the rise and the higher the maximum. Visual acuity increases at all dark adaptation times with increase in luminance. Implications of these findings for instrument lighting are discussed.
Report Availability
Not available via Contrails
Date Issued
1952-01
Index In
50 Years
Type
report