Nikon Rangefinder Lenses: The 3.5cm F3.5 W-Nikkor-C
First introduced for the original Zeiss Contax bodies and then the original Nikon I and among the original five lenses the 3.5cm F3.5 was arguably Nippon Kogaku's second oldest lens formulation for rangefinder cameras of those early days. Though that very successful lens formulation remained essentially constant for the more than a decade of that lens's availability, its physical embodiments varied enormously.
Pictured below are two embodiments representative of the earliest and the last evolutionary physical steps:
The one on the left has a number of curious issues represented. The serial number is, like certain other very early Nippon Kogaku lens variants, representative of the exact month and year of the lens's very first production. In its serial number 61244, the "6" is representative of the year 1946 while the "12" represents the month of December. The "44" is the actual serial number of production. It was the 44th attempt or initiation of lens production of this particular series. In his very fine 1981 work on these industrial works of art, Robert Rotoloni speculates that these lenses were probably for the original Nikon I but we disagree. Since when we first acquired the lens it was mounted on one of a pair of Zeiss Contax bodies (the other had a collapsible mount 5cm F2.8 Tessar mounted on it) that we acquired at the same time, we suspect the its intended use was in Nippon Kogaku's then early blossoming merchant after market.
As Rotoloni points out, the lens has a unique, for Nippon Kogaku, reverse mechanical turning aperture control mechanism.
It can be argued that since the onset production date for 612XX lenses preceded any of Nippon Kogaku's/Nikon's early rangefinder bodies, that these were very early after market lenses intended for Contax bodies of that era. That "cottage industry" company was too busy trying to pay its bills to build any lenses for which there was no ready market yet. Contrary to rumors that there is a shim correctable infinity shift differentiating the NikonBM lenses from ContaxBM lenses; there is no such shift between the two. Our measurements confirm identical focus (at infinity) for both types; and no such measurement can be used to determine which lens execution is for which body class, ContaxBM or NikonBM. However, as would show up most dramatically in later lens designs such as the 8.5cm f1.5, the effective screw pitch for the lens coupled to a body's parallax rangefinder system is enough different to cause very significant errors at close range when the two systems are mixed. This may actually have had a consequence in "depth of field" related issues discussed below. (The author would like to thank R. J. Rotoloni for insightful personal discussions as the author has attempted to gain a complete understanding of the events surrounding this early evolutionary period for Nippon Kogaku/Nikon.)
The lens on the right is the mechanical last evolutionary step in this lens's embodiments. The "F" stops obviously turns in the opposite direction and has the familiar click stops. It is a "BLACK" and amazingly, weighs almost exactly half of what its early predecessor does. One criticism that users of early NK lenses had was over weight and due to progressive changes in internal parts at first and later sets of complete make overs these lenses got progressively lighter in their progressive generations.
The lens on the left has a singular odd error in theory and/or execution recorded for all time as witness to how naive or unsophisticated these early craftsmen at Nippon Kogaku must have been in their art: the depth of field scale marked on the barrel(s) and emphasized with "tick marks" are just simply wrong. These should be physical scientifically determined demarcations and not the collective opinions of the particular lens designers of that time. Though it shows up in more subtle ways for all f-stops, it is most dramatically displayed for hyperfocus settings, especially at the minimum f-stop, f16 as illustrated.
Below are pictured four "910" series lenses, serial numbers 9101225 thru 9101741. All are MIOJ but only the ones in Nikon mounts have that designation probably since the Leica SM version has no obvious place for that engraving. BTW, the 9101740 and 9101741 are not only in sequence but according to Rotoloni very close to the last of this particular breed.
