tcmatthews said:
The 50mp sensor is medium format and Sony does not have a medium format camera system. They have worked with Hassleblad before. I think the state of Hassleblad financially was what lead to Pentax and PhaseOne also getting the sensor. The D800/D800E/D810 are Nikon and it has been proven time and time again that Nikon adds proprietary processing before writing data to the "RAW" file.
This is actually true of Canon now as well. DIGIC 6 processes the data before writing it to the RAW file. The 7D II will probably be fairly impressive at ISO 16000 for an APS-C camera. It'll be impressive because the data written won't really be truly "RAW"...it'll be cooked, just like a Nikon camera. The other thing Nikon does is clip blacks, instead of setting a bias offset. That tends to result in cleaner shadows, but it's discarding a little bit of data that could be useful in certain circumstances (such as astrophotography...which is the reason a hack was created to remove the black point clip and restore the bias offset, as it restores the linearity of the signal in Nikon cameras.)
For what it's worth, the A7s, a powerhouse at high ISO, also cooks the raw data. The BoinzX chip is very similar to the DIGIC 6 (I honestly don't know which has the superior design or approach...we'll have to see.) It too does noise reduction on the RAW data before writing it out to the file.
Cooking the RAW is probably going to be a standard practice now. Even if you reduce read noise, at high ISO, IQ is ultimately going to be photon shot noise limited. You can increase Q.E., but the high end sensors like the one in the A7s are already at 67%. There is maybe a third of a stop of "real" improvement to be made in the sensor itself by increasing Q.E. to 100% (which is doable, but expensive...at least currently...it may become cost effective at some point in the future.) Any other gains are going to have to be made either by increasing the sensor area (i.e. medium format sensor), or by processing the RAW data. For established camera systems, increasing the sensor size isn't an option...hence the reason everyone is cooking their RAWs now.