AVCHD vs MJPEG: Which is better?

[Mike Krumlauf]

I've never shot MJPEG with the GH cameras before, so I was wondering if there was any added benifit to using that codec over AVCHD. I've read about the 4:2:2 color space, but i'm not finding anything that says it is also 1080p and 24p. 720p i wouldn't mind (it would be like shooting the HVX200 again, in terms of resolution). Is there a stable 720p/24p 4:2:2 MJPEG patch floating around anywhere?

 

[Geoff Gilson]

Some differences of the top of my head:

MJPEG
Can be better at preserving grain in low-light shots (than low-bitrate long-GOP AVCHD)4:2:2 (only with hack)
30p native (but only 30p)
More consistent bitrate
Edits buttery-smooth
Dubious quality gain at "1080p" hack mode
Much more prone to aliasing

AVCHD
Noticeably better fine detail resolution
Can be cleaner looking at low ISO - less "dancing macroblocks"
Much more frame rate options (24/25/30/50/60)
Slow if editing native files, but can be transcoded

I would say try MJPEG if you're willing to try out something new.
If you shoot 1080p 24 AVCHD then down-res it to 720p, then you'll get more colour resolution.
The new I-frame AVCHD hacks for the GH2 are far better than MJPEG.

You can change the FPS from 30 to 24 in ptool, but the hack just skips every 4th frame. Motion is not fluid.