Almost all other Pentax K mount bayonet lenses will function properly under manual focusing, with the AF system providing focus indication – Asahi Optical called this TTL Electronic Focus. This includes lenses with the Pentax K-A mount (introduced 1983) and the K-AF/AF2 mounts. However, the newest SMC-Pentax FA J (1997) and SMC-Pentax DA (2004) types, lacking an aperture control ring, have severely restricted functionality. There were over thirty contemporary manual focus Asahi Optical made lenses of the SMC Pentax-M and SMC Pentax-A types.