Quite a few patches of this on the concrete fence posts in the garden, and it changes colour depending on the humidity. After rain they're quite green!
Canon 30D
Vivitar 100mm
Single flash on bracket with diffuser.
Grey lichen on fence post
Moderators: rjlittlefield, ChrisR, Chris S., Pau
Grey lichen on fence post
Canon 5D and 30D | Canon IXUS 265HS | Cosina 100mm f3.5 macro | EF 75-300 f4.5-5.6 USM III | EF 50 f1.8 II | Slik 88 tripod | Apex Practicioner monocular microscope