CAMERA SYSTEM, DRIVER/PASSENGER MONITORING SYSTEM, MOVING VEHICLE, IMAGE CAPTURING METHOD, AND NON-TRANSITORY STORAGE MEDIUM

A camera system includes an image sensor, a wavelength filter, and an imaging optical system. The image sensor has an image capturing plane. The imaging optical system is configured to have light coming from a subject passed through the wavelength filter and imaged on the image capturing plane. The wavelength filter has a perpendicularly incident region and an obliquely incident region. On the perpendicularly incident region, a principal ray, which has passed through the imaging optical system, is incident perpendicularly. On the obliquely incident region, a principal ray, which has passed through the imaging optical system, is incident obliquely. The image sensor has sensitivity to a light ray having a predetermined wavelength. The light ray having the predetermined wavelength is transmitted at a higher transmittance through at least a part of the obliquely incident region than through the perpendicularly incident region.