I have an older 70-300mm lens which I had used on my D7000, but was not sure if it worked on the Nikon Df. It does!
Foxtails are the seeds of a local wild grass. They are sharp and pointed, and manage to disperse themselves on the winds or by transportation. They can work their way into your clothes without your knowing it, are uncomfortable against your skin, and seem to work their way into everything. If you have a dog, keep it out of the foxtails – they have been known to bore into skin and cause infections. Not pleasant to be around, but they are really lovely backlit, with their slender stalks and foxtailish shape.