Image sensor and image capturing apparatus

An image capturing apparatus comprising:

• an image sensor comprising:
• a plurality of microlenses;
• and
• a pixel array having, with respect to each of the microlenses,
• a pair of first regions formed at a first depth from a surface on which light is incident,
• a pair of second regions formed at a second depth deeper than the first depth, and
• a plurality of connecting regions that connects the pair of first regions and the pair of second regions, respectively;
• and
• a focus detection unit that obtains pupil division signals respectively corresponding to divided pupil regions from signals output from the pixel array, and perform phase difference focus detection based on the pupil division signals,
• wherein a direction of arranging the pair of second regions corresponding to each microlens is a first direction, and a direction of arranging the pair of first regions is either the first direction or a second direction which is orthogonal to the first direction, and
• wherein the focus detection unit is implemented by one or more processors, circuitry or a combination thereof.