Upload & Sell: On
Anybody out there have the Nikon tripod collar yet?
I have the Nikon RT-1 collar ($159 from Aden Camera in Toronto).
The overall manufacturing quality seems to be on par with the third-party knock-offs I've seen for the Canon lenses, and not quite as good in terms of materials or finish as Canon's own collars. There's about a 2.5mm difference in the ID between the RT-1 and the Canon Tripod Ring A(B) with the Canon being smaller - not quite close enough to allow using the Canon collar on the Nikon lens.
The combination of the rather coarse flocking on the ID of the Nikon collar and the texture of the lens finish produces a result not unlike fingernails on a blackboard (but at a much lower pitch) when the lens is rotated in the collar.
Those minor issues aside, the collar does fit firmly and supports the lens rigidly with no flex or play whatsoever, which is exactly what one wants from a tripod collar, so I feel it was worth the money.