Abstract
Electronic display systems have been a boon to vision researchers for their flexibility as stimulus generators. However conventional displays only produce moderate luminance levels and limited contrast ranges. This constrains their utility as tools for exploring visual response over the vast levels and ranges we experience in the real world. Fortunately high dynamic range (HDR) displays are being developed that can produce luminance levels and contrasts on the order of those encountered in real world scenes. Typically, these displays use a LCD front panel with a spatially modulated backlight produced by a digital projector or LED array. One consequence of this design is that the backlight only shows a low frequency image, which limits the range of spatial frequencies that can be produced at high luminance contrasts. This reduces the value of these displays as visual stimulus generators. To address this problem we have developed a high resolution, high dynamic range display system for vision research that is capable of producing high luminance contrasts across a broad range of spatial frequencies. The display's front panel consists of a 30” Apple LCD monitor with 2560x1600 addressable pixels. The backlight image is produced by a tiled array of DLP projectors that we have corrected geometrically and colorimetrically using custom camera-based calibration software. The display is capable of producing spatial frequencies up to 12 cycles/degree (24” viewing) at luminance contrasts up to 40,000:1. We are using the display for material perception studies, where high intensity specular reflections are important, and for low vision research, where deficits often appear at extreme luminance contrasts. This display represents a useful new tool for vision research that can be constructed using commodity display hardware and standard image tiling methods.
This work was supported by the National Science Foundation.