At a certain time of year, the sun sets as seen from this window over a road about half a mile away, flanked with trees (which at this time of year are bare branches) either side. A quarter of a mile further away the same road loops back; perspective means the treetops of this part appear lower off the horizon. My brother took this photograph of the sun setting through the trees. The sun's disc is largely obscured by the branches; by setting the focus to be maximally unfocused the details disappear and all you can see is a gradient of blackness increasing towards the bottom of the photograph. Clever, eh?
Here's the real link!