I just returned from a 10 hour trek and wagged home an Omega D5-XL Dichroic enlarger. You bet I'm excited! The enlarger came with two lenses: a 150mm/5.6 Componon-S and a 50mm/3.5 Komuranon-S. No question that the Componon-S is a keeper. The only question I have is if there is an optinum f-stop for the lens? The Komuranon-S is an unknown quantity to me. I suppose it falls into one of 2 categories: OK for practice but replace as soon as possible OR a sleeper of a lens that works as well as my talents will ever need. Your thoughts?