You folks have covered lots of good points here, and I also agree with Justin's comments regarding how the "tests" relate to the photo making process.
Case in point: I bought the Mamiya 35mm lens, knowing that it would be a bit soft in the corners. When it arrived I wanted to see just how soft so I went to my driveway, set up tripod, leveled and paralleled everything, and shot my garage door as well as my brick wall. Well, I wanted to vomit. The corners were soft (as promised) and the barrel distortion was much more than I expected (and had not read anyone comment on). Now I'm not saying my 35mm lens is a bad copy, 'cuz it isn't. I just hoped that the reports would be a bit harsh instead of simply fair, as they were fair.
I took the 35mm lens to the American River the next day and shot some scenes that included rocks and boulders in the corners, processed them for printing, and the images are great for prints to just about any size I'd like. This is by far the softest of all of my Mamiya lenses, and in most shots the corners are useable for large prints if I get the rest right. I'd love it to be better, but it's serviceable.
My 80mm is sharper, for sure, (all of my lenses are), but my brick wall or garage door tests always disappoint me. In fact, I have never done a lens test, other than with macro lenses, that have left me feeling good. I now only do cursory test of lenses (especially since the 35mm) and then go and shoot various subjects to see how the lens works real-world.
In practical application (for landscape type work) I find the biggest hurdle with MFDB is getting the DoF right (deep enough). In my shots I come up against DoF issues long before I hit lens issues.
I hope that Tim find's the source of the problem and fixes it to his satisfaction. Like others have suggested, I would likely ask to compare another copy of the 80mm.
Best,
Dale
