Image capturing apparatus and method for controlling the same

An image capturing apparatus comprising:

• a pixel portion in which a plurality of pixels are arranged in a matrix, each of the pixels including a photoelectric conversion portion, a charge-voltage conversion portion configured to convert a charge of a signal transferred from the photoelectric conversion portion into a voltage, and an expansion portion configured to expand a capacitance of the charge-voltage conversion portion;
• a switching circuit configured to switch connection between the expansion portion and the charge-voltage conversion portion;
• and
• a read-out circuit configured to amplify signals of the a same pixel with a plurality of types of amplification ratios and read out the amplified signals,
• wherein when the read-out circuit amplifies signals of the same pixel with the plurality of types of amplification ratios and reads out the amplified signals, the switching circuit makes the connection state between the expansion portion and the charge-voltage conversion portion the same, for reading out operations with the plurality of amplification ratios, and sets the expansion portion and the charge-voltage conversion portion to be connected with each other if an S/N ratio of the image to be captured is prioritized.