Nikkor-P 1200mm f11

Version Serial no Date Screws Engraving Notes
F 120011 > Aug 64 - - LMIJ Early Nikon literature shows a model with a small rear element and no aperture ring. May be a prototype or very early production lens.
F < 120064 – 120173 > - 1966 - LMIJ Larger rear element and aperture ring. Early trials must have shown that the aperture in the focus unit is too far back for this lens, causing vignetting, so an aperture ring was added to the lens itself. When the aperture ring is used, the aperture on the focus unit should be set wide open.
F 121001? < 121014 – 121056 > 1966 - 1971 - LMIJ Based on production quantities of other telephoto lens heads and serial numbers collected, it is unlikely that over 1000 lenses were made between 120xxx and 121xxx, so this appears to be a new range. The reason for the change is unknown.
F 131001 > 131148 1971 - 1973 - LMIJ No lenses actually seen in this range so far..?
C 131401 < 131473 – 131588 > Sep 74 - Nov 77 - LMIJ Lens now multicoated with no further changes.

Version	Serial no	Date	Screws	Engraving	Notes
F	120011 >	Aug 64 -	-	LMIJ	Early Nikon literature shows a model with a small rear element and no aperture ring. May be a prototype or very early production lens.
F	< 120064 – 120173 >	- 1966	-	LMIJ	Larger rear element and aperture ring. Early trials must have shown that the aperture in the focus unit is too far back for this lens, causing vignetting, so an aperture ring was added to the lens itself. When the aperture ring is used, the aperture on the focus unit should be set wide open.
F	121001? < 121014 – 121056 >	1966 - 1971	-	LMIJ	Based on production quantities of other telephoto lens heads and serial numbers collected, it is unlikely that over 1000 lenses were made between 120xxx and 121xxx, so this appears to be a new range. The reason for the change is unknown.
F	131001 > 131148	1971 - 1973	-	LMIJ	No lenses actually seen in this range so far..?
C	131401 < 131473 – 131588 >	Sep 74 - Nov 77	-	LMIJ	Lens now multicoated with no further changes.