Fujinon makes a very nice (and very expensive) 1/2 to 2/3s adapter to allow the EX-3 to use B4 broadcast lenses--the ACM-21.

It seems to me that they also once made a cheaper, hard mount with no wiring for far less than the $1900 most folks want for the ACM-21...more like about $300 or so. However, other than the Mike Tapa mount, I'm not seeing any other options these days.

Any idea where I might find one of the cheaper adapters?

I've got one of the older non-powered 2/3 B4 to 1/2" adapters that I no longer use. You fit it to the EX3 1/2 adapter that comes with the EX3 or to a PMW-320. PM me if your interested.

TBH The powered adapters are much more useful (almost essential) on an EX3 as there is no way to drive the zoom or iris otherwise. The non powered adapters are fine on a PMW-320 as these have the extra lens power socket.

Sony makes a 2/3" adapter without the power connector for much less money.
http://www.bhphotovideo.com/c/product/49493-REG/Sony_LO32BMT_LO_32BMT_2_3_to_1_2_.html

If the Fujinon was the same price, it would be a no-brainer.... but since the only real thing I miss without the power connector was the servo zoom, I found a wonderful company (Jony Jib)
JonyJib Camera Solutions (http://www.jonyjib.com/)
who will make just about any adapter cable you need. In this case they made an adapter to connect my Canon broadcast 2/3" lens to one of the hirose power taps (they can also use d-taps) on my Bebob battery adapter. I now have full servo zoom control. (they also made an adapter to connect my stock Fuji lens to my Fuji zoom controller I've used on my Betacam for years.... MUCH better zoom control than using the rocker on the stock lens)

Of course using the Sony 2/3" adapter does not provide auto iris, but who uses that anyway? (that's what zebras and the histogram are for)

It's a low cost option anyway.... and my old broadcast lenses look spectacular on the EX3. Better than the stock Fuji lens. One word of warning to anyone using broadcast lenses on the EX3 however.... a good friend of mine who has been a lens technician longer than he'd want to admit has told me that the Sony lens mount on the EX3 is not structurally as robust as a broadcast camera such as a Betacam. (no big surprise there) He strongly suggests using the camera handle to lift and carry the camera as much as possible. Putting too much torque on the lens (such as using the lens grip to hoist the camera up on your shoulder) has resulted in several warped lens mounts on EX3s over time. So just be careful with that extra weight on there.... doubly so if you have a battery adapter using bricks or v-mounts, wireless receivers, and matte boxes. All of this adds significantly more weight, and more stress on the lens mount.

Final bit of advice: I find the backfocus tends to go out often on the stock lens.... just about any time you remove it. So it's a good idea to reset the backfocus any time you have switched lenses.

I was thinking a set of rails and a yoke or pin support for the 2/3 lens would make a degree of sense...

Alister: does the powered Fuji adapter also let you start/stop the camera from the lens grip?