While researching an old lens I was planning to put on eBay, I noticed a quote from Herb Kepler praising the lens for being "greatly superior in sharpness" compared to similar zooms. According to Johan J Ingles-Le Nobel on extreme-macro.co.uk, "At 80mm and f5.6 to f16 this lens is tack sharp, especially at close focusing distances which is unusual. It thinks it is a prime." The lens is the Tamron SP CF Macro 35-80mm Adaptall 2 zoom lens. Mine came with a Contax adapter, but I've never gotten my RTS III cleaned/fixed (the viewfinder looks like there's a camo net over it), so I'd never payed any attention to this lens. I didn't know of its reputation when I got it with some other stuff. It doesn't look like much, as you can see. And, while I know Tamron make some fine lenses, I knew nothing about this one. I have a number of Adaptall 2 adapters, including one for my Canon EOS cameras so, after seeing the reviews it gets, I decided to test it out before selling it off. I'd have to say that it deserves its reputation for excellence, based on my informal testing. I did NO post-processing, at all, other than the normal import sharpening. This was shot handheld at 80mm for 1/320 at f/8 and ISO 1600 (because I was using it inside, and forgot to change it when I went outside) with the front element of the lens approximately 3 inches from the flower. This is one macro zoom that really IS a macro! And it doesn't rely on switches or buttons to put the lens into "macro mode". You just keep turning the focus ring as you move closer. And here's a 100% crop from it. It's just as sharp as 200%, and almost as sharp at 300%, which tells me that this may be the sharpest lens I've ever owned. Here's one of the indoor shots that convinced me to do more testing. 1/60 at probably f/2.8 and ISO 1600, probably also around 80mm. And one more, with the same settings. It's not particularly the sharpness in these shots that made me investigate further, but the color rendition and "the look". I realize that is a useless descriptor, but I don't know how to describe it. It's partly the apparent depth, partly the illusion of 3-D, and probably some other factors. If you can describe it better, I'd love to be educated on this. I actually took it with me when I went out to run some errands, hoping to grab some more test images, but my battery went from half-charged to dead in about six shots, most of which were out of focus, because I was wearing the wrong glasses. But, the end result is that, since they don't command the prices they're worth, you won't be seeing mine on eBay any time soon.