Thank you Bernard. The images are stunning!
Thanks to all for the advice previously on ideal lens line-ups for a weekend city break. I ended up buying the Sigma 35mm f/1.4 and taking that with me to Paris along with the Nikon 16-35mm f/4, 50mm f/1.8 and 85mm f/1.4. I found that I used the 35mm and 16-35mm fairly often for architectural and cityscape shots, but had the 50mm on most of the time as I wandered the streets. Its size and weight made it the easiest to carry around and the image quality, especially for street photography, more than adequate. Some of my Paris images are on flickr at markdavisleica -
https://www.flickr.com/photos/124595163@N05/.
Numerous posts about longer telephoto zooms have got me reading all the reviews and it seems to me that nobody who gets the Nikon 70-200 f/4 is at all disappointed, or wishes they had gone for the considerably more heavy and expensive f/2.8. Please shout now if I am wrong about this, as I am going to get the f/4 this weekend.