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Northern LightsA. Lange & Söhne shows breathtaking impressions between light and darkness

The interplay of opposites culminates in perfection with the northern lights in the Arctic sky above Iceland. For A. Lange & Söhne's three luminous models, this is the ideal setting to showcase the spectacular contrast between light and darkness.

The trio of fascinating light virtuosos that accompanied the Nordic expedition earlier this year included the GRAND LANGE 1 MOON PHASE "Lumen", which was first presented in January 2016. In addition to the ZEITWERK "Luminous" and the GRAND LANGE 1 "Lumen", it is the third A. Lange & Söhne model with a semi-transparent sapphire-crystal dial. Its light-permeable coating allows the numerals to absorb a sufficient amount of light energy to uniformly glow in the dark for several hours.

How luminous displays workWatches with luminous displays need a light source that charges the luminous compound applied to the display elements and allows them to glow. Thanks to the semi-transparent black-tinted dial and an ingenious mechanism, the displays of the GRAND LANGE 1 MOON PHASE "Lumen" and of the other A. Lange & Söhne "Lumen" models can be permanently charged with light energy.

The displays of the GRAND LANGE 1 MOON PHASE "Lumen"The dial is made of blackened silver with generous apertures and a semi-transparent black-tinted sapphire-crystal glass wafer. The special coating applied to the glass blocks most of the visible light but not the UV spectra that "charge" the luminous pigments on the outsize date mechanism and cause them to glow in the dark. The tens cross is coated with a white luminous compound and printed with black numerals. Conversely, the units disc, also featuring black numerals, is made of transparent glass and rotates in front of the luminous background of the date aperture.

The lunar disc is made of glass. First, the glass surface is coated with a patented process. Then 1164 stars and the moon are cut out with a laser beam. The luminous compound behind the lunar disc makes the moon and the stars shine. The large moon-phase display occupies a prominent position on the main dial. Once properly set, it only needs to be corrected by one day every 122.6 years.

Why the northern lights are greenThe rare natural phenomenon can be observed in the polar region merely during a few days between September and March. Complex physical processes create the polychrome auroras in the upper strata of the earth's atmosphere. The green light, to which our eyes are particularly receptive, occurs at an altitude of about 100 kilometres. Here, oxygen atoms collide with the electrically charged particles of the solar winds. These collisions emit light with a wavelength of 557.7 nanometres, which the human eye perceives as green.

Photo shoot locations

Vík í Mýrdal – Black beachFascinating black: The beach at Vík í Mýrdal consists of black lava. Huge volcanic basalt mountains dominate Iceland's sea-battered coastline. This is the perfect setting for A. Lange & Söhne's three "Lumen" models: The black dials form an ideal background for the rhodiumed gold hands and appliques as well as the green shimmer of the luminous displays. This rich contrast ensures excellent legibility.

Langjökull – Mountains and glaciersInteraction of heat and cold: Glaciers are key features of Iceland's landscape. They cover about a tenth of the island's surface. The largest one is the Vatnajökull (English: water glacier). One of the island's most active volcanoes lies beneath its expanse of about 8100 square kilometres. The alternation of hot and cold extremes characterises A. Lange & Söhne's "Lumen" models as well. The platinum used to manufacture the case is heated to about 1800 degrees Celsius and then cast into a die while it is molten. Then it is rolled to achieve the final thickness of the bezel, case middle and caseback. Within 30 minutes, the metal cools down uniformly to room temperature, making it particularly resilient.

Haukadalur – Valley of the geysersThe force of steam: The Strokkur is among the most impressive geysers in the Haukadalur geothermal region. It erupts roughly every 15 minutes. Boiling water and searing hot steam are hurled up to 35 metres into the air. A wide variety of minerals, metals and plants can be found in its immediate vicinity. Sunlight brings out the saturated colours of sulphur, iron and mosses. Steam plays a pivotal role in the manufacture of A. Lange & Söhne's GRAND LANGE 1 MOON PHASE "Lumen": The dial and the lunar disc are coated with a patented vapour deposition process. It is responsible for the brilliant colour and crispness of the details.