Performance figures are reported on absolute luminance, luminance uniformity, characteristic display function,
internal scatter, dynamic range, distortion, modulation transfer and its spatial uniformity, and temporal and spatial
noise of two commercial ORT display systems as well as films printed by laser image recorders and displayed on
light-boxes. One of the ORT displays has a matrix of nominally 2000 x 2000 pixels, the other of 1000 x 1500 pixels.
The laser image recorders cover a matrix of 3500 x 2200 pixels.
When comparing equal pixel matrices of hard versus soft copy displays, typically hard copies facilitate greater
information transfer than soft copies due to a presentation with higher absolute luminance, greater perceived
dyiiainic range, and better spatial resolution. Perceived dynamic range and resolution are partially degraded in
the ORT displays by internal scatter. Soft and hard copy displays are about equivalent in terms of luminance
non-uniformity, noise, and geometrical distortion. All displays differ in their characteristic display functions and
thus in perceived contrast resolution.
A display function standard is proposed to the industry by which mismatches between hard and soft copy
presentations can be nimized as well as means for maintaining standardized performance.