[Brightcolours]

Note: the 25 and 11mp sRAW are not actually RAW at all. They do not contain RAW data and do not have the headroom of RAW either. Nikon's sRAW is already demosaiced and reconstructed (and downsampled from full res.), with 11 bits of data instead of the 14 bits of the full res. real RAW.

 

Canon's mRAW and sRAW also are demosaiced, reconstructed and downsampled from full res., but with 14 bits of data.

 

So think of the D850's sRAW as glorified (11 bits vs 8 bits (or 14 bits vs 8 bits with Canon)) JPEGs. One better uses the  12bit lossy compressed NEF option instead of sRAW, if space saving and WB and exposure headroom of RAW is important to you.