Photography system, camera, and photography illumination device

A camera, comprising:

• a first communication unit that communicates with a photography illumination device having a second communication unit;
• and
• a first control unit, wherein:
• the first control unit wirelessly transmits from the first communication unit to the second communication unit a first signal that commands a preparatory flash emission that precedes a main flash emission during photography;
• and
• when a second signal from the second communication unit is received by the first communication unit that includes flash emission timing information of the preparatory flash emission, and that carries information as to the effect that the first signal has been received, then the first control unit starts photometric processing during the preparatory flash emission based upon the flash emission timing information

A photography illumination device, comprising:

• a second communication unit that communicates with a camera having a first communication unit;
• and
• a second control unit, wherein:
• when a first signal is received from the first communication unit by the second control unit that commands a preparatory flash emission that precedes a main flash emission during photography, then the second control unit wirelessly transmits from the second communication unit to the first communication unit a second signal that includes flash emission timing information of the preparatory flash emission, and that carries information as to the effect that the first signal has been received.