Where are you seeing apco? It stands for Apple Codec. Use the movie inspector in the QT player.
You can make both optimized and proxy media. Optimized is ProRes 422. Proxy is ProRes Proxy and quarter resolution.
Honestly, if you have a decent graphics card and the MBP isn't too old, I won't both with either optimizing or proxy media with DSLR footage.
PS I assume your tech info is out of date, and you're not really using 10.5.6.
Thanks for the reply. I saw "apco" when I selected the .mov and clicked "more info" file using Finder and looking in the hard drive. But, yes, when I used the Movie Inspector in QuickTime it did come up as Pro Res 422.
My MacBook Pro is about 4 years old. I don't think my graphics card is so great anymore. I think my laptop has 2. One for "Better Battery Life" and one for "Higher Perfrormance". I was told by a tech who is also using this same laptop that the "HP" cards were junk when they were new and not to bother using it. I was having issues with my Cine Display when I tried it.
I'm back to using OS 10.6.8. after having tried Mountain Lion and having all kinds of problems, particularly with Capture One Pro.