Why not AIC?
 

It seems the general consensus for 5DmkII editing on the Mac the workflow to use is ProRes422. ProRes422 is indeed an excellent codec with lossless (at least to my eyes) quality. It does, however, bloat file sizes to extreme proportions. Additionally because the files are so large it creates issues trying to several streams (multicam) without a fast raid disk array.

Through experimentation with several different formats I found AIC (Apple Intermediary Codec) to be an excellent alternative. The quality (again- to my eyes) looks just as good as ProRes422, and this is examining the same frame at 100% magnification. Plus the file sizes are quite manageable. An original 5DmkII file that is 2.5gb in size is only 3.5gb with AIC...however a staggering 13.8gb with ProRes!

My question is why not AIC over ProRes?

I just did some testing of my own. Apparently the 4:2:0 of AIC rears it's head when you grade the footage.

Both identical shots with each codec, zoomed to 200% in FCP, with Magic Bullet grading:

http://www.msprotege.com/members/Laz...roresvsaic.jpg


However, viewed at 100% it is practically imperceivable. Yet along down-converting out to SD/DVD, and web.

To me it comes down to grading as well - if you're not doing any color correction, just cutting a video together, then AIC is probably a great choice. Since it's an 8-bit format it doesn't hold up as well once you start pushing it - you're more likely to get banding, etc. Once you CC everything you have to render & recompress it as well, and AIC doesn't seem to hold up to multiple compression passes as well as ProRes.

Unfortunately FCP doesn't let you render to ProRes in an AIC timeline like it does for HDV/XDCAM, as that would minimize these issues... in fact, XDCAM HD422 might make a better choice just for that reason - it would be similar or smaller file size to AIC, similar quality, but your sequence could render to ProRes. The only drawback would be heavier processing load while editing.

Hmm, I'll give some of the XDCam Presets a try. I'm not sold on the ProRes workflow.