So I recently bought a Omega D5 Dichro with an assortment of carriers and lenses. The other two lenses I got focus without an issue, they are 135mm and 150mm respectively, the third lens is a 50mm Nikkor that can't seem to focus on a flat lens board. I seem to get a rectangle with rounded boarders no matter what I try. I've inspected the lens for any type of hazing, but it looks clear as a bell. Could this be a function of using the improper lens board? Does it need a special extended board due to it's shortness? I really don't know where to start with this one. Let me know what you guys think!