I use f5.6 lenses for medium format and get good results. I think the quality difference comes from the number of elements in the lens construction, rather than the maximum aperture. The Componon is either 5 or 6 element which is at the higher quality end. The Componar, on the other hand, has fewer elements and does not give as good image quality(although it is still a good lens). Enlarger lenses are inexpensive at the moment, so it is worth doing some research and buying the best quality models. Good luck with your printing! Alex.