Apparatus comprising: a plurality of pixels arranged in rows and columns, a plurality of column sample lines, and a plurality of row sample lines, each column of pixels being connected in common to a different one of the column sample lines, each row of pixels being connected in common to a different one of the row sample lines, each pixel comprising: a photodiode arranged to generate an exposure signal representative of radiation incident on the pixel during an integration period; a sense node arranged to receive the exposure signal from the photodiode; a buffer amplifier arranged to receive the exposure signal from the sense node; a storage node arranged to store the exposure signal output from the buffer amplifier; a sample stage disposed between the buffer amplifier and the storage node and arranged to select whether the exposure signal is passed to the storage node;and a readout stage arranged to provide readout of the exposure signal stored at the storage node from the pixel responsive to a ROW SELECT signal on the row select line, the sample stage of each pixel comprising: first and second sample switches (50, 52) in series between the buffer amplifier and the storage node of the pixel, the first sample switch being connected to the column sample line of the pixel and the second sample switch being connected to the row sample line of the pixel, such that the exposure signal is only passed to the storage node at a time when both a COLUMN SAMPLE signal on the column sample line and a ROW SAMPLE signal on the row sample line are active. a plurality of pixels arranged in rows and columns, a plurality of column sample lines, and a plurality of row sample lines, each column of pixels being connected in common to a different one of the column sample lines, each row of pixels being connected in common to a different one of the row sample lines, each pixel comprising: a photodiode arranged to generate an exposure signal representative of radiation incident on the pixel during an integration period; a sense node arranged to receive the exposure signal from the photodiode; a buffer amplifier arranged to receive the exposure signal from the sense node; a storage node arranged to store the exposure signal output from the buffer amplifier; a sample stage disposed between the buffer amplifier and the storage node and arranged to select whether the exposure signal is passed to the storage node;and a readout stage arranged to provide readout of the exposure signal stored at the storage node from the pixel responsive to a ROW SELECT signal on the row select line, a photodiode arranged to generate an exposure signal representative of radiation incident on the pixel during an integration period; a sense node arranged to receive the exposure signal from the photodiode; a buffer amplifier arranged to receive the exposure signal from the sense node; a storage node arranged to store the exposure signal output from the buffer amplifier; a sample stage disposed between the buffer amplifier and the storage node and arranged to select whether the exposure signal is passed to the storage node;and a readout stage arranged to provide readout of the exposure signal stored at the storage node from the pixel responsive to a ROW SELECT signal on the row select line, the sample stage of each pixel comprising: first and second sample switches (50, 52) in series between the buffer amplifier and the storage node of the pixel, the first sample switch being connected to the column sample line of the pixel and the second sample switch being connected to the row sample line of the pixel, such that the exposure signal is only passed to the storage node at a time when both a COLUMN SAMPLE signal on the column sample line and a ROW SAMPLE signal on the row sample line are active.