The EBU tests cameras regularly for broadcast worthiness. It’s a great resource. All the cameras you mentioned should resolve 1000 lines. The Canon and Nikon DSLRs line-skip, hence the resolution loss. The GH2/3 resolves 1000 lines.
Funnily, there was a case a few years ago where the 4K RAW from the Red One passed testing, but the uncompressed SMPTE 292M 10 bit 1080p stream failed.
Resolution is important, but not as much as most people seem to think.
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