Thanks Erik … looks like that may well be it, the footage is lo-res H264 .mov that I’ve been sent, it’s ptc, green screen, and it’s for me to sue as a guide, I stick the information behind the presenter and send back the Hi-def ‘project’, they then ‘replace’ the lo-res and render. I don’t really need to render but I do need to review the project for timing etc and doing a ram preview is painfully slow (I don’t have a very powerful Mac) … converting 20 bits of footage will be a pain but yes I can do that … any recommendations codec wise please ? or is there something I can do during the render process which will achieve the same (given that said render is only for my own use) … thank you so much for easing the pain. Roger