Beginning with the amateur level Canon AE-1 of 1976, there was a complete overhaul of the entire Canon SLR line. The 1970s and 1980s were an era of intense competition among the major SLR brands: Canon, Nikon, Minolta, Pentax and Olympus. Between 1975 and 1985, there was a dramatic shift away from heavy all-metal manual mechanical camera bodies to much more compact bodies with integrated circuit (IC) electronic automation. In addition, because of rapid advances in electronics, the brands continually leapfrogged each other with models having new or more automatic features, and less expensive components and assembly. The industry was trying to expand out from the saturated high-end professional market and appeal to the large mass of low-end amateur photographers keen to move up from compact automatic leaf shutter rangefinder cameras to the more "glamorous" SLR but were intimidated by the need to learn all the details of operating a traditional SLR.