Quote Originally Posted by John Koehrer View Post
Carbon on the valves, Carbon on the valves!

If the lube's not visible on the blades then it's most likely on the blade operating ring or the housing for it.
This is the ring that the aperture blades are connected to. Waaay down deep in the nether regions of Hades. I mean your lens.

Well, John, if that is the problem, then maybe we need some Bardahl to take care of that "Dirty Sludge, Sticky Valves, Gummy Rings, and Blackie Carbon!"