I saw a question on another site and wanted to pose it here. (My paraphrasing.) It also made me wonder about a few other questions. 1. How can you tell that you are getting a late model enlarger lens? 2. Are there 'pro' versus non-pro models? Basically, what's the differences? In a regular lens line - like Nikon for example - the large aperture lenses are generally the 'pro' line with special glass, coatings, etc... Is it the same thing with enlarger lenses? 3. Does the brand matter? If so, why? Are there tests of enlarger lenses out there? 4. Actually, what makes a good enlarger lens? Large aperture? Special glass? Coatings? 5. Is there such a thing as a 'zoom' enlarger lens? Enquiring minds want to know.... Thanks in advance, Art.