Here is super fast C-mount TV zoom lens specially modified for use on Micro Four Thirds Panasonic GH2.
The Pentax 8-48mm f1.0 vignettes on the Micro Four Thirds sensor so you must use ETC/zoom mode on the GH2 for video use. 8-48mm becomes 40-250 35mm equivalent.
A 55mm to 62mm step-up adapter has been screwed onto the front threads so an existing Lumix lens cap can be used. Use low ISO. The lower the number the less noise there will be because the ETC mode zooms in 2.6 times. There is no image stabilization so it can be a bit shaky when zoomed in without a tripod. I can get noisy so I use Neat Video plug-in in FCP to clean up some of the shots.
This lens was purchased new from B&H Photo: bhphotovideo.com/c/product/341297-REG/Pentax_C60812_C60812_8mm_to_48mm.html
Modifications to adapt the lens mount were done by ed_lee83