What platform are you using? What is the specific format of your AVCHD footage? What sequence preset are you using? Why are you rendering?
Hey, thanks for the answer. I jumped the gun when I accused CS5 in poorly rendering/exporting MTS/AVCHD files. It was late, and the issue was with playback on Win7/ATI Radeon card, not CS5. (I recently upgraded to both) It's a wonder what a night's sleep will do!
Turned out the issue was a nifty little default checkbox in the ATI display settings which applied a "dynamic contrast" to video playback in some programs. So, I got bad looking footage coming out of flash playback and WMP. VLC and Chrome handled the video as they should. So, the lesson is: don't post at 2am and don't install ATI's bloated catalyst control center.
Hope this helps folks in the future!
Turned out the issue was a nifty little default checkbox in the ATI display settings
This is just one reason why QC is never done on a computer monitor, but on a burned disk (DVD or Blu-ray) played back on a properly calibrated CRT.