READ UPDATE AT BOTTOM
As a lucky owner of a Sony EX-1, i stumbled upon another good (maybe even better) hardware HD->SD downconversion method.
If you own a EX1, export your FCP sequence to XDCAM-EX (like in the previous walkthrough) and copy it back onto a EX1 memory card; configure your EX1 video output to deliver SD letterbox or framecrop, and play your movie from the EX1 ! Simple! You will have to record the output signal to a SD recorder, capture card or a professional broadcast quality sampling device to get it digital again.
Don’t laugh: i tried this with an old Sony 1 inch video taperecorder (once top-of-the-broadcast-bill), played it on my Philips plasma TV and it looked better (read: sharper) than any other SD output i’ve seen from my HD footage! Since this is a fully analogue picture, i find this conclusion pretty shocking!
Am i getting crazy, or is the hardware-and-rerecording way the only solution to get an acceptable SD down-conversion?
Just to get you started with a new discussion. Maybe some SD capturing device gurus out there can jump to it.
UPDATE: the amazing little program MPEG STREAMCLIP does the job very very good! Best software downconversion seen to date. For both MAC and PC: http://www.squared5.com/