I use it with my FX1. The 523Pro does not have iris control, but works nicely with focus and zoom.

I read somewhere that the "push-auto-focus" button resulted in some problems with some cams, but I think that was the V1, not the Canon.

I think the 503 is a much smoother head than the 501. When I have used 501's, camera moves always started with a lurch. I would be leery of using them in a situation where there are no re-takes. YMMV.

Best wishes,
Peter
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http://www.parkfilms.com

Thanks, Peter. I am now a proud owner of the 503 head along with the 315MVB2 legs. The combo is great and the head itself is really smooth, though I am just getting used to it.

I am looking for a very light head. I saw the manfrotto and it looks fine.

However, here is another one that worked great and weighs 1.26 pounds, the Gitzo 2180
http://www.bhphotovideo.com/c/produc...s_1_Fluid.html

A camera store here has it cheaper than B&H. It doesn't have a bubble, but it is very high quality and works well. It's made for sighting scopes and small DV cameras. I just mention it, because it seems like a good choice for travel, which I am looking for.

It is a Gitzo Series 1. The Gitzo legs are considerably more expensive than the heas, but it would work with other legs.