I have old 1/2" lens I use on my PAnasonic AG-DVC200 http://www.canon.com/bctv/products/pdf/yh16x7krs_for_us.pdf
will this work on EX3 or it is not good enough???

The Panasonic 1/2 inch lens mount is different to the Sony one so it won't fit directly and there is no way to operate the iris or zoom electronically. It's also an SD lens so would probably be a bit soft.