An Eyelash Fungus
These orange/brown discs were on a the barkless parts of a rotting branch resting on wet mud at the edge of a shallow pond.
The largest a few mm in diameter, it has upright hairs around the rim. They were shorter than they should be for the common species (in spite of the long shadows cast by the sun).
Olympus EM-1, (aperture priority), Olympus 4/3 50mm f2 macro, 50mm 1/160 at f7.1 ISO 200, hand-held.
Olympus EM-1 (aperture priority), Olympus 4/3 x2 TC, Olympus 4/3 50mm f2 macro, 1/125 at f7.1, 1/40 at f11 ISO 200, hand-held.
The stereos are crosseye.