I am wondering if anyone with a 70-200mm F4L with a Tripod mount ring could give me some dimensions as far as the internal diameter is concerned. The reason I ask is that I have access to a CNC milling machine, and since I am saving for the 70-200 and I want to get it ASAP I could make a ring that would fit the barrel to save about 100+ dollars. Any help you can give would be greatly appreciated. Thanks tons ahead of time,
Riley


