Here’s a closup of a lichen, which I believe to be Parmelia sulcata. Because it is a foliose lichen (one that is somewhat leafy), you cannot get it all in focus when you take a close photograph, so this picture is the result of 25 photographs, each focussed on a different part of the lichen. Software then picks out the sharp parts of each photograph, then joins them together to make one image.

Collected last Summer in Clocaenog Forest, North Wales.