Copal shutters go both ways - why?

[Steve Goldstein]

Maybe that title will get some eyeballs...

I happened to be holding a 200mm Nikkor-M and a 150mm Rodenstock APO-Sironar today and noticed that the order of the speeds is opposite for the two shutters. On one, speeds increase clockwise, on the other it's counterclockwise. My 90mm Nikkor-SW is the same direction as the Nikkor-M, another Rodenstock and a Schneider lens are opposite the Nikkors. These are all the original shutters for the lenses concerned. Basically, the Nikkors go one way, everyone else goes the other way.

I'd heard that Nikkors always came in "special" Copal shutters, which I thought just meant the body band (making it difficult to put new scales on one of their shutters). But it seems the special-ness extends to the innards as well. Other than being different, what's the point? It seems to me it would just drive up the cost of shutters to Nikon because their volume certainly would have been less than all other users combined. Unless Nikon owned Copal.

Any ideas as to the rationale behind this? Is it physically possible to use all the same internal bits and simply assemble the shutter upside-down? The release mechanisms work in the same direction, so it's not a complete mirror image.

Sign me..

.. puzzled

[Arne Croell]

Actually, thats not the case. The only thing that is reversed is the position of the marker (the red triangle) and the scale with the engraved times. In the Nikon case, the marker is engraved on the fixed barrel, and the shutter speeds move with the click stop ring, for the others the shutter speeds are engraved on the fixed position part and the marker moves on the ring. If you look at the lens from the front, turning the timing ring counterclockwise gives you shorter times in BOTH cases!

[Steve Goldstein]

Thanks Arne! I hadn't noticed that small detail, but now that I've looked more carefully I see what you mean. So really the difference is just two pieces that are engraved differently, everything else is the same. I wonder how much extra Nikon had to pay per shutter for the special parts? They obviously must have thought being different was worth it.

[Gordon Moat]

Oddly enough, many Nikon 35mm cameras (perhaps all?) use Copal shutters. After I got my 180mm Nikkor-W, I almost thought the same thing, that the shutter was backwards. After using it a while, I find that adjusting one shutter speed higher or lower without looking (just using click stops) functions the same as my Schneider 135mm in Copal 0.

Ciao!

Gordon Moat Photography