The Leica M6 from 1984 was the first M where the TTL exposure meter was integrated into the classic casing, thanks to advances made in the miniaturization of the electronic parts since the days of the M5. However, it still lacked a TTL flash exposure meter.
Leica integrated this feature into its successor that came onto the market in 1998 and was known as the M6 TTL. To have space for the measuring cell, the casing had to be 2.5mm higher. In addition to the standard 0.72 viewfinder enlargement, the M6 TTL optionally offered the 0.85 viewfinder enlargement introduced with the M6J – a special model from 1994 – which allowed for higher setting accuracy with focal distances as of 50 mm.
In addition, diverging from the previous model, Leica change the direction in which the shutter speed dial turned, so that the direction of the arrow would correspond to the exposure meter displays in the viewfinder. Last but not least, and following the example of the M5, the shutter speed dial was bigger. Up until 2002, about 40,000 copies of the M6 TTL were produced.