Figure 1
From: Increasing intensity directly increases the perceived warmth of primary colors
The optical system used for presenting the color stimuli at differing energy levels. The first lens (L1) focuses light through a circular neutral density wedge (W). That light passes through the colored filters placed in a rotating filter holder (FH). Light is relayed by the second (L2) and third lens (L3) through an electromagnetic optical shutter (ES) with an associated timer. The viewing surface for the subject (eye position stabilized with a chin and forehead rest, HR) is an optical diffuser (D).
