Minolta XD-7 with MD 50mm F1.7 lens and Winder.

In 1977, Minolta was the first manufacturer to combine both TTL aperture-priority and shutter-priority automation in one SLR camera body, this was the Minolta XD-7 / XD-11. The mode switch next to the shutter-speed dial has three positions: “M” (manual), “Auto – A” and “Auto – S”. The “A” indicates Aperture-priority mode and the “S” Shutter-priority mode. There is also a hidden Program-mode, securing correct exposure whenever the available aperture-range is insufficient, in which case the shutter speed is adjusted. In fact, this function is always active, checking the exposure immediately before the shutter is fired, by MEASURING the TTL light intensity AFTER the lens aperture is set automatically. Based on this reading, it ADJUSTS the shutter speed as required. To obtain full advantage of the Shutter-priority mode, the lens must be set to its minimum aperture. On the new MD-range of lenses, this setting can be locked by a small switch. Failing to do this, limits the range of apertures available to the automatic mode. There is a “Green line” assisting the correct use of the Shutter priority mode, comprising green symbols on the aperture ring and lock, the “S” mode switch position, and the 1/125 sec. on the shutter speed dial. However the green 1/125 sec. is just a suggestion, not mandatory.