Change the manual aperture value (f-number) on the camera
#include <camera/camera_3a.h>
camera_error_t camera_set_manual_aperture(camera_handle_t handle, double aperturevalue)
Use this function to set the manual aperture value. Setting a small f-number results in a reduced depth of field. Setting a large f-number results in an increased depth of field. The value that you set using this function is only applied when the exposure mode has been set to allow manual aperture settings using @c camera_set_exposure_mode(). You can use the @c camera_get_supported_manual_aperture_values() function to determine the range of valid aperture values that you can use. For more information regarding when manual settings take effect, see Manual Settings in the @e Camera @e Developer's @e Guide and @c ::camera_exposuremode_t. The viewfinder must be running before calling this function.
CAMERA_EOK when the function successfully completes, otherwise another camera_error_t value that provides the reason that the call failed.