An apparatus includes: a first pixel for acquiring an image, the first pixel including a first conversion element and a first thin-film transistor and connected to a first signal line; and a second pixel for correcting an output of the first pixel, the second pixel including an element and a second thin-film transistor and connected to a second signal line, in which a ratio between a plurality of capacitances related to the first signal line and a ratio between a plurality of capacitances related to the second signal line are approximately equivalent.