Originally Posted by Steve Rosen

Sure, if you can use the XL2's 16x manual on the H1 (which I do regularly) then the 20x will work fine on previous XL models... You will probably have to set the back focus manually though...

The 20x, although awkward to manually focus, is a pretty nice lens - some CA, which has been talked about often here, but not as bad as you might think from some of the posts - I just finished a commercial in SD that will be distributed nationally to Rape Crisis centers - I shot with the 20x in B&W and it is really pretty stunning. I was surprised at how good it looked (B&W often looks like crap in video).