I have a Bessa 3a with 40mm f1.4. Liked it so much I treated myself to a Leica M7 as a retirement present to myself! Beautifully made and in a league of its own. I also thought the price of S/H leica lenses was unaffordable. So bought some S/H voigtlander ones. 35mm f2.5 is small and pin sharp. Bought a 50mm f1.5 Nocton off ebay (39mm screw thread) and cheap adaptor ring. Bit big but great lens for low light. Now added S/H 28mm f2 (ebay) and S/H 75mm f2.5 (screw mount). Also got S/H Rokkor M 90mm f4. Heard that this is the same design as Leica 90mm f4. I have bought many second hand lenses for all sorts of cameras on the grounds that glass never wears out no matter how much light goes through it! My final money saving DIY tip is this - but be very careful. The screw thread lenses focussed slightly beyond infinity when adaptor was fitted and the focus mark was not at the top when the lens was mounted on the camera (Voigtlander and Leica). Sorted this problem by use of a small amount of plumbers thread tape wound VERY CAREFULLY on the thread of the lens.