"Diaphragm vibrations"? Good lord. Is the mirror/shutter silent? That's another one making the rounds.
Where do these questions come from? Is there a room full of obsessive-compulsive worry warts somewhere?
I didn't even know there was such a thing. Reminds me of pixel peepers in the digital crowd. OMs are a joy to use, I can handheld it at 1/15th with acceptable results. Your going to use a tripod so 1/8 is no problem.