Long story short, I'm looking for a cheap 75mm or 80mm enlarging lens in standard threaded mount. I found an inexpensive Voss 75mm f/3.5 lens, but I can't find any info on it. Can anybody tell me anything about it, specifically if it is a standard 39mm threaded mount? I'm not too concerned about optical quality since the lens will be used for 6x6 Holga negs. EDIT: perhaps I have spoken too soon. I've done a little more thorough Google search and lots of people are badmouthing the Voss lenses. What, specifically, are its flaws?