equivalent focal lengths
 

using a full frame 35mm lens on an EX-3 gives a 5.5 times magnification.

What about a 2/3" video lens? What mag factor can I apply?

Thanks

1.3x
Of course you also have to buy the ACM-21 adapter ring for close to $2K.

Depending on what you need from the lens you can also use the ACM-19 (supplied with the EX3) with a 3rd party 1/2 to 2/3" adapter. This generally works out a lot cheaper than the way overpriced ACM-21, but you don't get iris control and you only get servo zoom if you power the lens from an external battery.