Part of latitude is noise: by the time we hit ISO 51k, usable dynamic range is appears to be somewhere around the 7-7.5 stop mark (the amount will vary with your tolerance to noise); I can’t see any difference between ISO 100-400, there’s 1/2-2/3 stop loss at ISO 800, and roughly 2/3 to a whole stop thereafter. For a full size file, I place the usable limit at 12.8k for color, and 25.6k for monochrome. ISO 6400 will clean up almost completely with some NR. This is unheard of for medium format – and represents an excellent performance for cameras in general. At the pixel level, I’d say this camera is perhaps a stop cleaner than the D800E – not surprising given the newer photosite architecture and 20% (or possibly more) light collecting area – 5.3um pixels play 4.88um pixels. If you don’t need a full size file, oversampling and downsizing to 16MP – comparable to say the E-M1 and D4 - will yield some surprises: ISO 51k is very, very clean. It’s so clean I’d say it looks something like a ISO 2500 file from the E-M1, and an ISO 12.8k file from the D4 – and of course thanks to the downsampling, fine detail is much better, too. Food for thought for the reportage shooters – I certainly intend to make full use of this.