To obtain a suitable amount of main emission light even when an optical accessory for varying the color characteristic of transmitting light is attached in front of a light emission section of a luminaire.

A camera body 100 determines the amount of main light emission by carrying out weighing of a photometric value obtained based on a preliminary light emission of a stroboscope 300 according to information indicating a preset amount of preliminary light emission. The stroboscope includes a light source 402 for emission of light when a color filter is attached to a flash light emission section and chromaticity information is derived according to the light emitted from the light source and transmitted through the color filter. The stroboscope derives a light reduction amount for the flash light emission section according to the chromaticity information, determines a correction preliminary light emission amount by correcting a preliminary light emission amount at the light reduction amount for light emission and transmits the information indicating this correction preliminary light emission amount to the camera body instead of the information indicating the preliminary light emission amount.