I've been reading some posts about 16x9 adaptors that work with the GL2 and it seems that there are 3 options. 2 of them are not fully zoom through and the new Century is fully zoom through (and also quite expensive).

Looking at Adam Wilt's reviews of the 2 non zoom through adaptors, I got the impression the Optex was slightly better with it extra zoom range and all. But then I read a post on this forum (an old post I believe) where someone complained that his Optex adaptor was outputed an incorrect aspect ratio. Is this true? Has anyone else noticed this with their Optex 16x9? If so, then does the Century non-zoom through also have this problem?

And while I'm asking questions about the adaptor, how much can you zoom through with the optex/century before it starts to get impossible to focus?

I have the Century, and I never zoom more than a quarter of the way in, so if you rely on the zoom a lot, then it would be pretty limited. You could zoom a little farther, but I don't see any reason to chance it, and I've never gotten around to doing resolution tests to figure out where the lens loses focus. I really don't mind it so much because I find wide angles much more useful. I went for the Century over the Optex because of the vignetting issues, which I feel are way more serious than having a little extra zoom range. As far as whether or not the Optex gives you the exact correct aspect ratio, I don't see how it matters since nobody but you would ever notice, and if it did bother you that much you could fix it in post easily.