Capturing Luminous Flux Entering Human Eyes with a Camera, Part 1: Fundamentals
Siqi He, Hankun Li, Yonghong Yan, Hongyi Cai
Abstract
A space occupant’s real-time exposure to light reaching his/her eyes has been a concern in lighting research and design practice. This study assumed a schematic eye to estimate the luminous flux received by the entrance pupil from the visible luminous environment. As the first part of this study, this paper focused on the fundamentals of luminous flux calculation that considers real-time human eye reactions. The research work includes: (a) developing a dynamic binocular/monocular visual field model that takes the eye movement into account, based on a conventional visual field model in orthomode, (b) retrieving the apparent area of the entrance pupil of the schematic eye, and (c) quantifying the light passing through the entrance pupil from the luminous environment fallen in the binocular/monocular visual field. The fundamental theory was tested in a theoretical uniform lighting scene to calculate the luminous flux emitted from the human visual field along multiple gaze directions at different light levels. A foundation was thus laid to estimate the real-time luminous flux passing through the entrance pupil with the aid of the camera as disclosed in Part 2 of the present study.