A system includes a window treatment adjacent to a window of a room. At least one motor drive unit is associated with the window treatment, for varying the position of the window treatment. A sensor measures a light level (e.g., an outdoor light level) at the window. A controller provides signals to the motor drive unit to automatically adjust the position of the window treatment so as to control a penetration distance of sunlight into the room when the window treatment is partially opened. The controller is configured to position the window treatment in a bright override position if the measured light level is at least a bright threshold value. The controller is configured to select the bright threshold value from among at least two predetermined values. The selection depends on an angle of incidence between light rays from the sun and a surface normal of the window.