sentences:  Similarly, some AF-I & AF-S lenses will not work on some older Nikon AF film SLRs.The Nikon 1-mount was announced on 21 September 2011 together with the Nikon 1 series high-speed mirrorless interchangeable-lens cameras.The Pentax K-mount (or just "PK mount") was created by Pentax in 1975, and has been used by all Pentax 35 mm and digital SLRs since.