1. A camera system, comprising: a camera that includes an image sensor and a filter mask; and a control and evaluation device that receives an image signal output by the image sensor, wherein: the image sensor includes an array of sensor pixels outputting pixel signals, the filter mask includes an array of filters that are situated in front of the sensor pixels and have different wavelength-selective transmission responses, a portion of the filters includes attenuation filters including blue filters for transmitting light in a short-wave wavelength range, and another portion of the filters including red filters, blue sensor pixels, in front of which in each case one of the blue filters is disposed, output blue attenuation pixel signals, and red sensor pixels, in front of which in each case one of the red filters is disposed, output red pixel signals, the image signal output by the image sensor has a first subsequence of first frames taken with a first exposure time and a second subsequence of second frames taken with a second exposure time, the second exposure time is greater than the first exposure time, and the control and evaluation device evaluates the blue attenuation pixel signals of the second subsequence, but omits evaluating the red filter pixels of the second subsequence, to recognize signal sources whose light signals have at least one of: a signal period which is greater than the first exposure time, or a signal frequency which is greater than a readout rate of the image sensor.