Nikon's most recent 35mm film SLR lenses, the AF Nikkor G type (2000) lacking an aperture control ring; and the AF Nikkor DX type (2003) with image circles sized for Nikon's DX digital SLRs, will mount but will not function properly. A few exotic fisheye lenses from the 1960s require mirror lock-up and therefore an auxiliary viewfinder is preferred. IX Nikkor lenses (1996), for Nikon's Advanced Photo System (APS) film SLRs, must not be mounted on any F2, as their rear elements will intrude far enough into the mirror box to cause damage even with the mirror locked up.