Version | Serial no | Date | Screws | Engraving | Notes |
---|---|---|---|---|---|
Ai | 920001 < 920131 � 930610 > | 1977 - | 5+ | LMIJ | Thick rear protector, long projection from max aperture post prevents it fitting TC-16. |
Ai | 931001 < 931318 � 945542 > | - | 5+ | MIJ | Thin rear protector, no projection from max aperture post. Start serial number from TC-16 manual. |
Ai | < 939039 � 959393 > | - | 3+ | MIJ | Only three screws used in lens mount. |
Ai | 105001 < 110055 � 193558 > 193574 | - Aug81 | 3+ | MIJ | New serial number. Focus ring with squarer front edge, compared to sloping edge for previous versions (Ai 28/2.8 had similar change). Aperture coupling prong made of pressed sheet metal instead of solid metal. |