Sony Z1U & FCP Capture/Transfer

This camera has the option to downconvert HDV to SD as you are capturing it in FCP. It's handled by the camera itself and I'd recommend avoiding it as it gives poor results. You will get much better results capturing your footage in Pro res, and ken has ample advice on doing this. Having edited your footage compressor will output far better SD footage as long as you follow Ken's guidelines.
If it's shot in HDV then you need a HDV deck to see it. I really don't know what happens if you set the camera to 'downconvert' then hook it up to a SD deck ??
Simple solution is to use the camera and FCP to capture it.