Probably a no name brand since it vignette's like a lot of them do. This is why shooting B&W is one of the best "CHEATS" out there. The worse your original color footage is, the better a B&W shot it could make. To me, the best B&W should be gritty, dirty, edgy...this vid is a great example. Overexposed, washed out, doesn't matter in B&W.

On both cams, GH1&2, if you shoot max iso in B&W, you get a noisy image, but the noise looks like regular film grain with no FPN. Perfect for night shoots. You can easily use 3200 iso on the GH1 and 12000 iso on the GH2. GH2 footage shot in BW, I think in Vibrant, in EXT mode and it also had that grainy look. Use that during the day.

I've only done some tests with the GH1 and B&W Smooth makes iso 3200 usable. Not sure of GH2 outside what that link says.

EDIT: Posted above just seeing the B&W, just got to color and even the color footage has a nice grainy old school 16mm look to it. Cheap CCTV lenses and 16mm processing go great together.

@CRFilms I've just watched the video, great video ;)

As far as the use of cheapy 25 mm cctv lens for gritty B&W, I think that these fast lens (in particular 25mm, which is 50mm eq) having a central zone very sharp let to increase contrast.The only problem is the "bohek" too peculiar, too smooth at the corner, however I think that cropping the footage at 4:3 (most 16mm film use this 1.33 ratio) would be interesting..

Another video shooted with cctv 25 mm 1.4 and...little GF1: these cameras have a smaller sensor, so they don't present a huge distorsion/vignetting.. not grainy, however a bit of Cinegrain 200... ;) I think that GF1/GF2, at highest ISO + 25 cctv 1.4 could become very interesting and compact camera for "street shooting"...

Might even be not a cheap CCTV lens, but a Kern Switar. Great glass, but made for 16mm and a 25 will be soft in the corners and vignette mildly. Longer ones don't vignette, but a 10mm will vignette massively.