Nikkor-PC 10.5/ 2.5 - brass or alloy?

[Sonnar2]

The black "enamel" surface of a Nikkor lens PC 2.5/10.5cm (around 1955) - is it enameled brass or alloy? The color looks much thicker than the anodized alloy stuff of Canon or Pentax lenses of the same (or slightly later) vintage.
Probably the Nikkor 1.5/85 and later 2/85 RF barrell surfaces are made in the same matter. All lenses are black. Is the later (black) 2/85 lighter in weight than the previous (all chrome) version ?
The 2.5/105 is so heavy I believe the barrell can't be other than brass made. But my feeling could me mistaken (the Sonnar design contains a very thick third element)

cheers, Frank
http://www.taunusreiter.de/Cameras

 

[Sonnar Brian]

I suspect the first version is mostly brass, it is much heavier than the 2nd version. Both are heavier than the 1st generation SLR lenses, which had the identical optical formula. Remember that the first generation Nikkor lenses "the all-black" lenses were heavier than those that followed in the Sp era. Those later lenses used more aluminum. An "all-black" 13.5cm F3.5 lens is much heavier than the "chrome and Black" lenses that followed.

 

[VinceC]

The black 2/85 is considerably lighter than the chrome 2/85. That's true for all Nikkor lenses that began as chrome and were reissued in black barrels around the time the SP was introduced. Black versions can be as much as 50 percent lighter. The story in the Robert Rotolini book is that when the lenses were introduced, weight equalled quality, so the lenses were built with large amounts of brass. By the time the SP was introduced, professional users -- who often carried a full assortment of lenses -- had complained about the weight, and the lenses were lightened.

 

[Sonnar Brian]

Also, according to Rotoloni the 10.5cm F2.5 stayed the same weight throughout its run. My early verion is LTM, and it is a lot heavier than the S-Mount. It has a longer barrel and a tripod mount. I have an early (f16) 8.5cm F2 that uses thicker brass than the later all-chrome lens.