I upgrade from a Durst M 600 to a Omega D2v so I can print my 4x5 negatives. I have a 50mm lens that came with the enlarger and I had a 150mm lens around Schneider Componon? the old one with a metal look? I made a lens holder with a plastic and stick the lens into the enlarger to test. The problem comes when I try to focus. The smaller image I get that is on focus is around 19" by 15". It doesn't seem right, I want to be able to start printing 11x14 but in no way I can get a sharp image that size. I also changed the variable condenser lupe up and down just in case, but the position seems right, all the way up is where is supposed to be. Is my plastic holder inaccurate? Any advice will be appreciated. Cheers, Jaime.