The Mamiya/Sekor Auto XTL was introduced in April 1971. It was the first shutter priority auto-exposure 35mm SLR camera with both spot and average TTL metering systems inherited from the Mamiya/Sekor DTL series cameras. The ES series lenses used a bayonet-type mount instead of the M42 screw mount of the TL/DTL series cameras.
The Mamiya Auto X-1000 (without the Sekor name) was introduced in 1975. In most functions it is similar to the Auto XTL but features all-black finish instead of black-and-chrome of the Auto XTL.