Figure 1. Apparatus.

A) Schematic view of the high-dynamic range display. A DLP projector projects an image onto an LCD display panel through a Fresnel lens and diffuser, placed directly against the backside of the panel. Because the LCD panel is a transmissive display, it provides a multiplicative attenuation of the projector image, resulting in an overall dynamic range that is nominally the product of the native dynamic ranges of the projector and panel. The observer viewed the resulting image monocularly through an aperture and a reduction screen. The dotted portion of the reduction screen in diagram shows the vertical extent of a square aperture in that screen. The display is built following the design by Seetzen et al. [9]; details on its calibration are available in a technical report by Radonjić et al. [10]. B) The matching chamber was diffusely illuminated by a fluorescent bulb and contained a matching palette. The palette consisted 19 glossy papers ranging from Munsell N 0.5/ to N 9.5/. A baffle prevented light from the bulb from reaching the observer directly. Observers matched the test square, presented in the center of a checkerboard, to one of the palette papers. They indicated their response using a slider on a custom response box (shown below chamber in diagram). The slider varied a number displayed on an LCD panel mounted at the back of the viewing chamber. Out of range response options were displayed as text on the same monitor. C) The stimulus was a 5 × 5 checkerboard. The checker squares had CIE chromaticity x = 0.309, y = 0.338 and varied in luminance. The test, which was the center square of the checkerboard, took on 24 different luminances during each block of trials. Additional detail on the experimental procedures is provided in the supplement.