Technically, MOV files are *not* AVCHD. They can, however, contain the H.264 codec. AVCHD is a very specific form of H.264, with a specific folder and file structure.
Depending on your computer's specifcations, you may be just fine editing the native MOV files in CS5.
What Jeff said. I use MOVs from a 550D/T2i with no problems at all. With hardware MPE, I can stack several of these along with accelerated effects, and have realtime playback.
It will depend largely on the hardware capabilities of your computer, however; you need a pretty spry processor and a good chunk of RAM to be able to handle these (and other H.264-encoded media) effectively. Fortunately, even a budget box can be capable of this.
When I import the clips and place them on the timeline, a yellow bar is shown instead of green. I suppose this just means that the composition settings don't match, but even just previewing the clips in Premiere has a bit of stutter/lag.
So you suggest I purchase some hardware which can handle the job, but is there are filetype and codec which Premiere would prefer it to be?
They always show yellow; don't sweat it. Everything is going to be rendered on export, anyway. What matters is performance in the sequence; are you able to playback and edit the clips fluidly?
What are the specifics of your computer hardware?
Oh I see - my specs are Windows 7, Athlon 64 X2, 4GB RAM and a 256mb NVidia Graphics card. I suspect my graphics card is at fault here then
Yes, your graphics card is very weak and is the primary culprit. However, Athlon systems are less than preferable for editing video anymore. Used to be they were king of the pile, but Intel has far surpassed them. If you'll be doing a lot of editing you may want to consider upgrading your system signifcantly and switching to an Intel chip.
Just FYI, your playback will be smoother if you'll right click on your monitor (works in both source and program monitors) and select "Playback resolution" then reduce it to 1/2 or 1/4. It'll look a little artifacty, but it will play more smoothly and the artifacts will not be in your final encoded file.
Also, FWIW, it's my understanding that with the .mov wrapper on your file, you're losing CS5's ability to work in 64bit, which will also hamper your editing ability. That said, I'd probably be more likely to live with that than to transcode to an intermediate.
One of the beauties of CS5 is that it doesn't have a "favorite" of codecs like Final Cut does...
You'll also want to consider upgrading your memory if you do go to a new computer. Minimum 12GB memory for editing HD, is what I would say. Many here are running as much as 24GB.
It's the processor, not the graphics card. The graphics card will have practically zero effect on simple playback of these files, since hardware MPE doesn't do anything when it comes to decoding the files. It's all CPU, at that point.
But, yeah--your processor is just way too old and slow to sustain tolerable editing with this media. Throwing money at a new GPU won't get you very far, so save your pennies and dimes for a new computer.
In the meantime, you could transcode these to something like P2 MXF DVCPROHD using AME. They'll be larger than the originals, and require more drive bandwidth, but the CPU requirements are far lower. You can batch these in AME, but do a test to make sure that even these will work with your system. It's also adding a second layer of compression on the files, but if you have to edit, you have to edit