DETERMINATION OF WIDTH AND LUMINANCE OF CATHODE-RAY-TUBE TRACE

Abstract

A method is described for specifying CRT traces in terms of visual measures of width and central luminance. Trace width is measured with an image doubler which produces 2 parallel images of the CRT trace; width is defined in terms of the distance between the centers of the 2 images when they just appear to merge. Central luminance of the trace is measured with a magnifying system in conjunction with a Macbeth illuminometer. The magnifier produces a real image of the trace sufficiently enlarged to fill the field of the Macbeth. Matching is performed in the usual way; the appropriate conversion factor is applied to the Macbeth reading. Estimates of intra-observer and inter-observer variability are given for width and luminance measures. The method of measuring central luminance is compared experimentally with an alternative method involving a direct monocular match.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1952
Accession Number
AD0012018

Entities

People

  • Howard B. Ranken

Organizations

  • Columbia University

Tags

Communities of Interest

  • Biomedical

DTIC Thesaurus Topics

  • Air Force
  • Boundaries
  • Calibration
  • Cathode Ray Tubes
  • Color Temperature
  • Errors
  • Light Sources
  • Luminance
  • Measurement
  • Medical Laboratories
  • Observers
  • Standards
  • United States

Fields of Study

  • Physics

Readers

  • Human-Computer Interaction (HCI).
  • Vision Science/Vision Psychology/Cognitive Neuroscience.