+1, nice pics. When I saw the first one I thought 'wow, sharp. That Sigma works really well' - but then I saw it's the 85mm f1.8. I assume it's the Nikon? I bought that too. A great lens.
For the brolly, I thought that's an image printed on it!
rowland, I don't know how experienced you are so apologies for mentioning this, but these images above may have been processed moderately in Lightroom and Photoshop to bring the colours back to what you are seeing now.
I have to say that I'm quite happy with the colours my D800 produces - but sometimes the colour just is lost a bit due to type of light. But it can easily be brought back in Lightroom.
30 years ago I had an analog Contax SLR, it took wonderful pictures. The colours were always so bright, vivid and natural, I loved it. No matter whether I used Agfa, Fuji or Kodak - the colour characteristics were a bit different, but the resulting colours were always beautiful. Even a cheap film offered by a local photography franchise shop produced great pictures.
Then I had to replace the camera, I bought the exact same model, I used the same films, the same lenses, the same filters (in those days UV filters were common), but no luck - the colours always looked somewhat pale, bland.
I sent the camera to Contax for checking and adjustment, and they did what they could, but it didn't change, the colours in the images taken with this camera never reached the quality of the colours of the previous Contax.
From that I conclude that apart from the light in which you take pictures, there simply is some variance within the cameras of the same series. I don't know where it comes from, but I think it exists. Some cameras within one series will take nicer pictures than others, IMHO.