A camera device attached to a vehicle, the camera device comprising: a first image sensor configured to sense an image based on light acquired by a first camera; a second image sensor configured to sense a second image acquired by a second camera; and a processor (830, 170) in communication with the first image sensor and the second sensor, the processor (830, 170) configured to set a regular exposure time of the image sensed by the first image sensor based on a brightness level and a distribution value of brightness of the image acquired by the first image sensor and to set an exposure time of the second image sensed by the second image sensor, wherein the processor (830, 170) is configured to detect, verify, and track a tunnel around the vehicle based on the first image from the first image sensor and the second image from the second image sensor, wherein the processor (830, 170) is configured to control the exposure time of at least one of the first and second image sensor (820, 825) to be gradually increased when the vehicle goes into the tunnel, and control the exposure time of at least one of the first and second image sensors (820, 825) to be gradually decreased when the vehicle comes out of the tunnel, wherein the processor sets the exposure time of at least one of the first and second image sensor (820, 825) to be longer than the regular exposure time based on the brightness level and the distribution value of brightness of the image acquired by the first image sensor in a case that: a first front lamp region formed by a front lamp of the vehicle during travel of the vehicle in nighttime is partially overlapped with a second front lamp region formed by a front lamp of a second vehicle on the opposite lane approaching the vehicle, thereby constituting an overlapping region, and a front lamp region formed by the front lamp of the vehicle during travel of the vehicle in nighttime reaches the rear of a preceding vehicle. a first image sensor configured to sense an image based on light acquired by a first camera; a second image sensor configured to sense a second image acquired by a second camera; and a processor (830, 170) in communication with the first image sensor and the second sensor, the processor (830, 170) configured to set a regular exposure time of the image sensed by the first image sensor based on a brightness level and a distribution value of brightness of the image acquired by the first image sensor and to set an exposure time of the second image sensed by the second image sensor, wherein the processor (830, 170) is configured to detect, verify, and track a tunnel around the vehicle based on the first image from the first image sensor and the second image from the second image sensor, wherein the processor (830, 170) is configured to control the exposure time of at least one of the first and second image sensor (820, 825) to be gradually increased when the vehicle goes into the tunnel, and control the exposure time of at least one of the first and second image sensors (820, 825) to be gradually decreased when the vehicle comes out of the tunnel, wherein the processor sets the exposure time of at least one of the first and second image sensor (820, 825) to be longer than the regular exposure time based on the brightness level and the distribution value of brightness of the image acquired by the first image sensor in a case that: a first front lamp region formed by a front lamp of the vehicle during travel of the vehicle in nighttime is partially overlapped with a second front lamp region formed by a front lamp of a second vehicle on the opposite lane approaching the vehicle, thereby constituting an overlapping region, and a front lamp region formed by the front lamp of the vehicle during travel of the vehicle in nighttime reaches the rear of a preceding vehicle. a first front lamp region formed by a front lamp of the vehicle during travel of the vehicle in nighttime is partially overlapped with a second front lamp region formed by a front lamp of a second vehicle on the opposite lane approaching the vehicle, thereby constituting an overlapping region, and a front lamp region formed by the front lamp of the vehicle during travel of the vehicle in nighttime reaches the rear of a preceding vehicle.