Nikon Nikkor Ai 28mm f3.5

Completely revised model compared to the pre-Ai version. The new optical design has a similar 6-element configuration with a smaller front element and larger rear, which gives more even illumination than before.

Version Serial no Date Screws Engraving Notes
Ai < 104143 > - 5+ LMIJ Prototype shown on instruction sheet with different serial number. Appears identical to production lens.
Ai 1760201 < 1760632 – 1775022 > Jan77 - 5+ LMIJ Thick rear protector, long projection from max aperture post. Start serial number from F601 service manual
Ai < 1776176 – 1785355 > - 5+ LMIJ Thin rear protector, long projection from max aperture post.
Ai < 1785006 – 1798041 > - 5+ MIJ Thin rear protector, long projection from max aperture post.
Ai < 1799123 – 1954294 > - Sep81 3+ MIJ Thin rear protector, no projection from max aperture post. Somewhere around 186xxxx the aperture coupling prong was made from thinner pressed sheet metal.

Version	Serial no	Date	Screws	Engraving	Notes
Ai	< 104143 >	-	5+	LMIJ	Prototype shown on instruction sheet with different serial number. Appears identical to production lens.
Ai	1760201 < 1760632 – 1775022 >	Jan77 -	5+	LMIJ	Thick rear protector, long projection from max aperture post. Start serial number from F601 service manual
Ai	< 1776176 – 1785355 >	-	5+	LMIJ	Thin rear protector, long projection from max aperture post.
Ai	< 1785006 – 1798041 >	-	5+	MIJ	Thin rear protector, long projection from max aperture post.
Ai	< 1799123 – 1954294 >	- Sep81	3+	MIJ	Thin rear protector, no projection from max aperture post. Somewhere around 186xxxx the aperture coupling prong was made from thinner pressed sheet metal.

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Review by Ken Rockwell