An apparatus comprising: a pixel array comprising pixel cells, each pixel cell including: a respective source follower transistor (Tsf); and a respective floating diffusion node coupled to a gate terminal of the source follower transistor (Tsf); wherein a first pixel cell (210a of the pixel cells includes a first source follower transistor (Tsa), and wherein a second pixel cell of the pixel cells includes a second source follower transistor (Tsn); a detector module coupled to the pixel cells via a first bit line and second bit line, the detector module including circuit logic to receive both a first signal from the first pixel cell via the first bit line and a second signal from the second pixel cell (Tsn) via the second bit line, wherein the detector module is configured to indicate, in response to a first pulse of the first signal, a detection of a first random telegraph noise event in the first source follower transistor (Tsa), wherein the detector module is further configured to indicate, in response to a second pulse of the second signal, a detection of a second random telegraph noise event in the second source follower transistor (Tsn), wherein the first pulse and second pulse each include a respective discrete period of a fluctuation in a current or a voltage; a counter module coupled to the detector module, the counter module including circuit logic configured to perform a first count update in response to the indicated detection of the first random telegraph noise event and to perform a second count update in response to the indicated detection of the second random telegraph noise event and, based on both the first count update and the second count update, to communicate a number corresponding to a plurality of random telegraph noise events; and control logic configured to transition the apparatus between a first mode and a second mode, wherein during the first mode, the apparatus is configured to generate the number corresponding to the plurality of random telegraph noise events, wherein, during the second mode, the apparatus is configured to capture an image based on respective signals from the first pixel cell and the second pixel cell. a respective source follower transistor (Tsf); and a respective floating diffusion node coupled to a gate terminal of the source follower transistor (Tsf); wherein a first pixel cell (210a of the pixel cells includes a first source follower transistor (Tsa), and wherein a second pixel cell of the pixel cells includes a second source follower transistor (Tsn); a detector module coupled to the pixel cells via a first bit line and second bit line, the detector module including circuit logic to receive both a first signal from the first pixel cell via the first bit line and a second signal from the second pixel cell (Tsn) via the second bit line, wherein the detector module is configured to indicate, in response to a first pulse of the first signal, a detection of a first random telegraph noise event in the first source follower transistor (Tsa), wherein the detector module is further configured to indicate, in response to a second pulse of the second signal, a detection of a second random telegraph noise event in the second source follower transistor (Tsn), wherein the first pulse and second pulse each include a respective discrete period of a fluctuation in a current or a voltage; a counter module coupled to the detector module, the counter module including circuit logic configured to perform a first count update in response to the indicated detection of the first random telegraph noise event and to perform a second count update in response to the indicated detection of the second random telegraph noise event and, based on both the first count update and the second count update, to communicate a number corresponding to a plurality of random telegraph noise events; and control logic configured to transition the apparatus between a first mode and a second mode, wherein during the first mode, the apparatus is configured to generate the number corresponding to the plurality of random telegraph noise events, wherein, during the second mode, the apparatus is configured to capture an image based on respective signals from the first pixel cell and the second pixel cell.