ABSTRACT
remarkable structure of the eye—five million light-receiving elements—defining detail limits-candle-power—the “foot-candle “—the meaning of “lumen”—what is contrast?—gradation ratios— fechner’s law—daylight and artificial light intensities—the “photon”—seeing detail in daylight—action of the iris—the motion of television images — the size of the pictures — apparent brightness—the question of colour.
