In manual mode, a green M LED came on. The OVER or UNDER LED would blink to indicate the exposure adjustment recommended by the meter, while a steadily lit LED showed the actual camera set shutter speed. The photographer would adjust the shutter speed and/or the lens aperture f-stop until the OVER or UNDER LED went out. Unlike most other SLRs of the era, the ME F used two push buttons to increase or decrease shutter speeds instead of the traditional dial and this LED scale is the only display of the set shutter speed. What appeared to be a shutter speed dial on autoexposure M-series SLRs was actually the exposure mode dial: AUTO meant aperture priority and M was for manual.