NOTE: This definition was changed in RP-16-17 Addendum 4. Deletions have a strike-through. New text is bold.
For most purposes, it may be assumed that the distribution of luminance in the field of view can be described as if there were a single point of observation located at the midpoint of the baseline connecting the centers of the entrance pupils of the two eyes. For many problems it is necessary, however, to regard the centers of the entrance pupils as separate points of observation for the two eyes.
A single point located at the midpoint of the baseline connecting the centers of the entrance pupils of the two eyes.« Back to Definitions Index