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