Datograph Up/Down “Lumen”
Datograph Up/Down “Lumen”
24 Hours. Infinite Facets.
Limited to 200 timepieces
24 hours of inspiration. An infinite variety of perceptions. The DATOGRAPH UP/DOWN “Lumen” has more than one face. Changing with the light in the course of 24 hours, it reflects the vibrant atmosphere of every moment. From understated technicity through architectural elegance to a mysterious aura, it projects a captivating impression at any occasion – with a passion that never sleeps.
The DATOGRAPH UP/DOWN “Lumen” is the fourth model in a series of timepieces that make a bold design statement with the help of scientific knowledge. The three most prominent elements of its balanced face – the characteristic outsize date and the two subsidiary dials – form an equilateral triangle. At night, the luminous elements turn the distinctive design into an iconic beacon.
The DATOGRAPH UP/DOWN “Lumen” underlines the innovative power of A. Lange & Söhne in the development of pioneering chronographs. It combines the classic column-wheel design with a precisely jumping minute counter and a flyback function – mechanisms that are rarely found due to their complexity.
The harmonious architecture of the dial reflects the aesthetic equilibrium of the movement. The Lange outsize date and the two subsidiary dials for the seconds and the minute counter form an equilateral triangle.
This distinctive constellation already made the first DATOGRAPH, launched in 1999, a timeless fixed star. Due to its quintessential immaculacy in function and design, it enjoys cult status among purists, as does the DATOGRAPH UP/DOWN that was updated in 2012 with a power reserve of 60 hours and a power-reserve indicator.
The DATOGRAPH UP/DOWN “Lumen” takes the idea to the next level. Thanks to its semitransparent dial that exposes the ingenious disc ensemble of the outsize date and a luminous compound that causes all displays to glow in the dark, the iconic configuration unfolds a new aesthetic dimension.
The solution is a special coating on the semitransparent sapphire-crystal dial. It filters out most of the visible light, but not that part of the UV spectrum which is needed to charge the luminous pigments with enough light energy to keep them glowing uniformly in the dark. The transmission of light in the visible spectrum is attenuated to such a degree that, during the day, the sophisticated disc mechanism and the exquisite finishes are clearly exposed while ensuring good readability.
Composed of two separate display elements, the outsize date glows immediately after the date change at midnight as well. This is made possible with a luminous tens cross and a black printed units disc made of transparent glass which rotates above a luminous background. The fascinating midnight switching sequence can be observed in detail.
An exquisite mechanical universe.
The clearly configured semitransparent dial of the DATOGRAPH UP/DOWN “Lumen” allows a view of the sophisticated technology that controls the outsize date. Handcrafted details like the perlage on the entire surface of the main plate or the sunburst decoration on the date bridge can be clearly recognised.
The most astounding effect of the lavishly finished manually wound calibre L951.7 is its incredible depth. Indeed, the chronograph movements of A. Lange & Söhne have often been likened to architectural works of art.
The sapphire-crystal caseback allows the most interesting switching sequences to be observed. It exposes the column wheel that controls the stop functions, the flyback mechanism and the minute-counter lever for the precisely jumping minute counter.
A patented construction advances the minute-counter hand of the 30-minute totaliser by exactly one graduation every 60 seconds, even if the time measurement happens to be stopped during the zero passage. This guarantees a precise minute-counter reading at all times.
Lange’s proprietary cam-poised balance wheel, paired with a freely oscillating Lange hairspring, beats at a frequency of 18,000 semi-oscillations per hour. In combination with the 300-marker minute scale, this allows time measurements with a resolution of one-fifth of a second.
The “Lumen” models
“Lumen” is the name of a series of four timepieces that make a vibrant design statement with the help of the newest scientific knowledge. The first was the ZEITWERK “Luminous” launched in 2010 followed by the GRAND LANGE 1 “Lumen” and the GRAND LANGE 1 MOON PHASE “Lumen” presented in 2013 and 2016, respectively. All models were limited platinum editions and soon turned out to be coveted collectors’ items.
GRAND LANGE 1 “Lumen”
GRAND LANGE 1 MOON PHASE "Lumen"
Datopgraph UP/DOWN "Lumen"
The technical challenge encountered in the development of the “Lumen” models was to charge the luminous elements, including those hidden beneath the dial, with light energy. The solution is a sapphire-crystal dial coated with a semi-transparent compound that is permeable to ultraviolet light.
The transmission of light waves in the visible spectrum was attenuated to achieve a high-contrast, perfectly legible dial. On the other hand, light waves in the UV range can pass through. This allows the dials of the “Lumen” models to glow in the dark for several hours.