Upload & Sell: Off
I got a Hawk's knock-off on ebay. It was around $35 USD, and the build is terrible. All thin aluminum, very loosey-goosey as the helicoid extends out to the point there was wobble. It was a springless friction mount, and I also made the mistake of rotating the lens the wrong way to get it off, such that the lens mount dug into the aluminum and scraped off the black paint. That said, it was really cool seeing what the ZM25/2.8 could do with close focus. The detail was ridiculous. I'm considering going all in and getting a Hawk's.
Matt, nice cacti. The Voigt 90 is a super sharp little lens. Was the adapater you got by any chance the "L.M.E." one? I have been doing some research on it and have heard some similar comments.