Patent ID: 7715706

Claim:
An imaging apparatus including an infrared cutoff filter which is capable of being inserted into and extracted from an incident light path to an image sensing device, comprising: detecting means for, when the infrared cutoff filter is off the incident light path to the image sensing device, detecting whether the difference between current illuminance of a subject acquired from an image signal of the subject sensed by the image sensing device and a reference value of the illuminance of the subject after the infrared cutoff filter was extracted is equal to or greater than a threshold value; and filter control means for, when the detecting means detects that the difference between the current illuminance of the subject and the reference value of the illuminance of the subject is equal to or greater than the threshold value, inserting the infrared cutoff filter into the incident light path to the image sensing device, wherein the reference value of the illuminance of the subject is determined by calculating the average of values of the illuminance of the subject of a plurality of frames detected after the infrared cutoff filter was extracted from the incident light path to the image sensing device.