Very large-scale integral imaging (VLSII) systems utilizing multiple micro-optics arrays and display devices can be used for wide viewing angle 3-D displays. We analyze the distortion of 3-D integral images when micro-optics arrays are placed on a spherical surface and are used in direct pickup integral imaging. We show that 3-D orthoscopic real images with non-negligible depth always suffer from image distortion, while orthoscopic virtual images do not. Also, nonplanar (curved) display panels and image sensors are not currently available. We propose a solution to remedy this problem by placing a spherical lens in front of a planar lenslet array.