|Brocken Spectre & Glory
Images by Colin Richards above the glacial lake of Llyn y Fan Fawr in the western Brecon Beacons, Wales on Saturday 13th December, ‘14.
A ghostly shadow looms below the ridge, its head surrounded by concentric rings of colour. We know that the Brocken Spectre is merely the shadow of the walker. But surely all is not right here? The walker has arms outstretched horizontal. The Brocken has its arms at an angle? Each observer sees their own personal spectre and glory. The Brocken shadow visible here is that of the photographer not that of the photographed. Images ©Colin Richards, shown with permission
|The photographer looks straight down the shadow tube. Perspective renders the legs and arms greatly elongated. The shadows and rays can be thought of as a form of anticrepuscular rays with the observer inside the shadow. The unexpected appearance in mist, the distortion and the occasional surrounding by a glory combine into an unearthly sight.
The name originates from sightings by early climbers of the Brocken in the Harz Mountains of Germany, a place of frequent mists.
|A Glory.. ..is a wave rather than geometrical effect. Waves enter small mist droplets and somehow emerge after deflection through 180 degrees or so.
The main wave path is one where they are internally reflected once. This is an impossible path for geometric optics and part of the route involves waves along the drop surface.
Other wave paths with 10, 6 and 5 internal reflections contribute. The glory diffraction pattern is wavelength dependent, hence the coloured rings.
The best glories with many rings are from the almost monosized droplets of freshly formed fog.
The photographer casts a long, almost parallel, tube of shadow through mist lower down the mountain.