I'm probably spilling some beans here, but man, it's such a sweet deal and you guys have to jump on it if you shoot m4/3 cameras..
One of my favourite lenses that I've owned for my FD system has been the 35-105 f3.5 FD lens. It's relatively sharp through the range, affordable as hell, a bit weighty, but plenty useable. paired with my 50, it's the only other lens I take when I'm shooting my canon system, and it works pretty alright on 35mm.. a bit soft wide open out of the center, but it's a nice lens to take with me when shooting film on my FD setup.
This entire last week I've been shooting landscape video using a friend's GH3, along with this lens - that cost me a whole 40$ on ebay, I might add...
Simply put, it's basically like having a manual focus 70-210 f4 lens on a 5D/6D, but for 1/10th of the price of even an used 70-200 f4L, when adapted onto the GH2/3/4/whatever. it gets perhaps a LITTLE soft at the long end, but good god, everywhere else, even wide open, it's awesomely sharp enough for video purposes. It's parfocal, it's fixed aperture at f3.5 (which is plenty fast) and did I say it's CHEAP?
Seriously. Pick one of these up, guys..