M4 corridor bridge, serving Chepstow, being renumbered the M48, although the area is still generally considered as falling within the M4 corridor. Since the start of the 21st Century there has been evidence of more investment west of Cardiff, such as: M4 corridor The M4 corridor is an area in the United Kingdom adjacent to the M4 motorway, which runs from London to South Wales. It is a major high-technology hub. Important cities and towns linked by the M4 include (from east to west) London, Slough, Bracknell, Maidenhead, Reading, Newbury, Swindon, Bath, Bristol, Newport, Cardiff, and Swansea. The area is also served
Leica M4 The M4-2 added a hot shoe and motor drive compatibility as standard, but removed the self-timer. The M4-2 was followed in 1981 by the M4-P, which added framelines for 28 mm and 75 mm lenses. The range continued with the Leica M6 in 1984, which was essentially an M4-P with through-the-lens (TTL) light metering. The M4 finally ceased production in 1998, although Leica released a special edition with a high-magnification finder in 1998. Leica M4 The Leica M4 is a 35 mm rangefinder camera produced by Ernst Leitz GmbH. The M4 started production in November 1966, as the direct successor