Photopic vision corresponds to roughly which luminance range?

• A. 10^4 to 10^8
• B. 10^-5 to 10^-3
• C. 10^0 to 10^2
• D. 10^6 to 10^9

Answer: (A)

Photopic vision is cone-mediated vision that operates under bright lighting, allowing color perception and high visual acuity. At these higher luminances, the rod system is effectively saturated and does not contribute to the image. The standard luminance range associated with photopic conditions runs roughly from 10^4 to 10^8 candela per square meter. This covers daylight and very bright artificial lighting. In contrast, much lower luminances belong to scotopic (very dim) or mesopic ranges, where cones are less dominant or both rods and cones contribute. Therefore, the range 10^4 to 10^8 cd/m^2 best matches the photopic level.