An image pickup element comprising: a pixel array having: a plurality of pixels arranged in rows and columns; a plurality of signal lines allocated to each column for transmitting a pixel signal read from a pixel, wherein for each column at least two signal lines of the plurality of signal lines are provided, wherein a first signal line of the at least two signal lines is allocated to first pixels of the respective column for reading a first pixel signal of the first pixels and a second signal line of the at least two signal lines is allocated to second pixels of the respective column for reading a second pixel signal of the second pixels; a control unit configured to provide at least two pixel signal reading modes which are different from each other with respect to a frame rate and to perform control, in a first pixel signal reading mode of the at least two pixel signal reading modes, to read the first pixel signal from the first pixels connected to the first signal line of each column and to perform control, in a second pixel signal reading mode of the at least two pixel signal reading modes, to read the second pixel signal from the second pixels connected to the second signal line of each column and to transmit the read pixel signals via the respective signal line, thereby providing two-stream reading for output of two lines of data at different frame rates; and wherein a number of the first pixels allocated to the first signal line of the at least two signal lines and a number of the second pixels allocated to the second signal line of the at least two signal lines are different from each other, thereby a thinning ratio of the first pixel signal reading mode of the at least two pixel signal reading modes corresponding to the first signal line of the at least two signal lines and a thinning ratio of the second pixel signal reading mode of the at least two pixel signal reading modes corresponding to the second signal line of the at least two signal lines are different from each other. a pixel array having: a plurality of pixels arranged in rows and columns; a plurality of signal lines allocated to each column for transmitting a pixel signal read from a pixel, wherein for each column at least two signal lines of the plurality of signal lines are provided, wherein a first signal line of the at least two signal lines is allocated to first pixels of the respective column for reading a first pixel signal of the first pixels and a second signal line of the at least two signal lines is allocated to second pixels of the respective column for reading a second pixel signal of the second pixels; a plurality of pixels arranged in rows and columns; a plurality of signal lines allocated to each column for transmitting a pixel signal read from a pixel, wherein for each column at least two signal lines of the plurality of signal lines are provided, wherein a first signal line of the at least two signal lines is allocated to first pixels of the respective column for reading a first pixel signal of the first pixels and a second signal line of the at least two signal lines is allocated to second pixels of the respective column for reading a second pixel signal of the second pixels; a control unit configured to provide at least two pixel signal reading modes which are different from each other with respect to a frame rate and to perform control, in a first pixel signal reading mode of the at least two pixel signal reading modes, to read the first pixel signal from the first pixels connected to the first signal line of each column and to perform control, in a second pixel signal reading mode of the at least two pixel signal reading modes, to read the second pixel signal from the second pixels connected to the second signal line of each column and to transmit the read pixel signals via the respective signal line, thereby providing two-stream reading for output of two lines of data at different frame rates; and wherein a number of the first pixels allocated to the first signal line of the at least two signal lines and a number of the second pixels allocated to the second signal line of the at least two signal lines are different from each other, thereby a thinning ratio of the first pixel signal reading mode of the at least two pixel signal reading modes corresponding to the first signal line of the at least two signal lines and a thinning ratio of the second pixel signal reading mode of the at least two pixel signal reading modes corresponding to the second signal line of the at least two signal lines are different from each other.