I wrote a post over on DPR about the GM1 electronic shutter resulting in lower dynamic range, it is only outputting 10 bits RAW instead of 12 bits. Thought I'd mention it over here, if you need the most DR at base ISO don't use the electronic shutter if possible on the GM1 (e.g. pushing shadows a lot). Likely not a major issue in normal day to day photography. It is expected the GH4 may have the same behavior as its sensor datasheet indicates 10 bit only when doing the fast electronic shutter and they are advertising the camera as using the fast mode like the GM1 does. Sample pictures and longer description in the DPR post: http://www.dpreview.com/forums/post/53300241 Please read that post before asking questions here.