Image capturing apparatus and method for controlling image capturing apparatus

An image capturing apparatus capable of attaching to a detachable converter lens and executing autofocus detection of an imaging optical system, the image capturing apparatus comprising:

• a processor;
• and
• a memory containing instructions that, when executed by the processor, cause the processor to perform operations comprising:
• converting information for correcting a change in a focus state caused by aberration of the imaging optical system, wherein the information relates to an in-focus position of the imaging optical system for each of a plurality of different spatial frequencies, based on a change in spatial frequency caused by a magnification of the converter lens in a case where the converter lens is mounted;
• calculating a correction value for correcting a result of the autofocus detection, using the information that has not been converted in a case where the converter lens is not mounted, and using the information that has been converted in a case where the converter lens is mounted;
• and
• controlling a position of a focus lens provided in the imaging optical system, based on the result of the autofocus detection that has been corrected using the correction value.

A method for controlling an image capturing apparatus capable of attaching to a detachable converter lens and executing autofocus detection of an imaging optical system, the method comprising:

• converting information for correcting a change in a focus state caused by aberration of the imaging optical system, wherein the information relates to an in-focus position of the imaging optical system for each of a plurality of different spatial frequencies, based on a change in spatial frequencies caused by a magnification of the converter lens in a case where the converter lens is mounted;
• calculating a correction value for correcting a result of the autofocus detection, using the information that has not been converted in a case where the converter lens is not mounted, and using the information that has been converted in a case where the converter lens is mounted;
• and
• controlling a position of a focus lens provided in the imaging optical system, based on the result of the autofocus detection that has been corrected using the correction value.