I've search the data place but came up empty. I'm in need of a 50mm lens for my RZ. I am just wondering if the ULD is worth the extra cash. Many say the ULD is much sharper compared to the non ULD. I currently have a 65mm (non L/A version) and in my opinion, it's damn sharp. Is the non ULD 50mm just as sharp or should I go with the ULD?