Shown above is the 902nd 10.5cm f4 preset lens in F mount. This lens is optically identical to its twin brother in rangefinder mount. The lens hoods for both versions are interchangable. Most of the reference books I have read seem to suggest that the hood marked with "Nippon Kogaku" is proper for the F mount version, while the hood marked with only "Nikon" is for the rangefinder. (Reflex version does have earlier serial numbers.) Unlike the other early lens hoods for reflex lenses, no 10.5cm f4 lens hood is marked with the Gothic letter F. The total production number of this lens is unknown, but is estimated to be at around 5,000 units (my educated guess!), starting from No.405001. The serial numbers of the rangfinder version range from around No.408500 to No.411000. Within this range, I personally know of No.409355 and No.409373 that exist in F mount! Does it mean Nikon produced this lens under the same set of serial numbers but in two different mounts? Possible but I think more research needs to be done.

   

The serial number "405902" suggests that this is the 902nd lens made for the F mount.

     
                   
This early example has the recess guide rail on the lens base which can only be found on very early lenses. Apart from the "Tick Mark" lenses, I remember having seen early 2.1cm f4 come with this guide rail too. The later production of both 2.1cm f4 and 10.5cm preset no longer have this guide rail. This rail is there to guide the lens locking pin into the hole. A rather pointless feature that was later on abandoned.
                   
What makes this rare lens even more interesting and absolutly one of a kind is a mis-engraving on the lens barrel! This particular mis-engraved lens appeared on Issue NHS-80 of the Nikon Historical Society Journal.
 
Mis-engraved 10.5cm f4 ( No "S" )
   
Correctly engraved lens
 
                         
    Unique filter size of 34.5mm           Dedicated leather case with recessed top cover  
   
10.5cm preset lens in its hard to find original box with matching serial numbers!
         
       
 
             
           
Updated on 17 Dec 2013