An optical apparatus includes: a first focus detection unit that detects a focusing condition of an image forming optical system through a first focus detection method and outputs a first focus detection signal; a second focus detection unit that detects the focusing condition of the image forming optical system through a second focus detection method different from the first focus detection method and outputs a second focus detection signal; a focus adjustment unit that executes focus adjustment for the image forming optical system based upon either the first focus detection signal or the second focus detection signal; and a notification unit that alters a focus detection method notification in correspondence to the focus adjustment that the focus adjustment unit executes.