A lens apparatus is detachably attachable to an image pickup apparatus. The lens apparatus includes a notification unit configured to notify the image pickup apparatus of a type of the lens apparatus, and at least one processor or circuit configured to execute a plurality of tasks including a communication task configured to communicate with the image pickup apparatus. Via communication with the image pickup apparatus, the communication task transmits setting information for setting a white detection area to a white detection area different from a white detection area that corresponds to the type of the lens apparatus and is stored in the image pickup apparatus.