But what also needs to be noted is that the image quality of the Nikon 28-300mm lens is superb despite the 10x range. The D800 has a notoriously demanding sensor given its 36MP resolution yet the 28-300mm lens rarely feels like a budget option.
Even a 500mm lens hardly gets you there at this distance so my set up was a Sigma 500mm f4.5 with a Sigma 2x teleconverter making for a 1000mm f/9 lens. Despite mounting the lens on a tripod, at this magnification, the merest hint of a breeze seems to cause an earthquake within your viewfinder and forget touching the camera/shutter button, a cable release then was a must. What's more, at this distance over fields warmed by a summer's day, atmospheric disturbances and heat hazes can really deny you sharp focus in your final image. More than a few shots ended up in the waste basket but the shot below saw everything come together in a moment of calm and even at 100%, it holds up to scrutiny.
Of all the shots taken that day in Oxford, this is my favourite, because it's so hard to get. Planning, persistence and application of technique came together and paid off. It's a classic view of this university town, but one that 99% of visitors to Oxford will never see or capture. That alone makes it special.