For over 25 yrs I am using Nikon equipment and lately decided to try the Leica R system. Well, before it’s all gone… I’m going to buy R9 and wondering what type of lenses is compatible with this body. I know that R9 has electric contacts (ROM) to provide interface between a lens and camera CPU and all latest Leica lenses have ROM contacts. But how about the previous versions – 2 CAM, 3 CAM (BTW, what does CAM mean?) without electric contacts? I’ve heard that they are compatible with R8/R9 too. But how? Fully or partially? Will I loose any function/modes/settings attaching 2 or 3 CAM lens to R9 body? Is it similar to what we have in Nikon system when using Ai/Ai-S lenses with some AF cameras you might not have some exposure and metering modes? And any general advice about Leica lenses selection for R9 will be appreciated.