We measured accommodation responses under integral photography (IP), binocular stereoscopic, and real object display
conditions, and viewing conditions of binocular and monocular viewing conditions. The equipment we used was an
optometric device and a 3D display. We developed the 3D display for IP and binocular stereoscopic images that
comprises a high-resolution liquid crystal display (LCD) and a high-density lens array. The LCD has a resolution of 468
dpi and a diagonal size of 4.8 inches. The high-density lens array comprises 106 x 69 micro lenses that have a focal
length of 3 mm and diameter of 1 mm. The lenses are arranged in a honeycomb pattern. The 3D display was positioned
60 cm from an observer under IP and binocular stereoscopic display conditions. The target was presented at eight depth
positions relative to the 3D display: 15, 10, and 5 cm in front of the 3D display, on the 3D display panel, and 5, 10, 15
and 30 cm behind the 3D display under the IP and binocular stereoscopic display conditions. Under the real object
display condition, the target was displayed on the 3D display panel, and the 3D display was placed at the eight positions.
The results suggest that the IP image induced more natural accommodation responses compared to the binocular
stereoscopic image. The accommodation responses of the IP image were weaker than those of a real object; however,
they showed a similar tendency with those of the real object under the two viewing conditions. Therefore, IP can induce
accommodation to the depth positions of 3D images.