The new A. Lange & Söhne model tells the time reliably around the clock, and its stop function can be used at any time as well. This is because all indications (yes, all of them) of the Datograph Up/Down Lumen are legible even in darkness, thanks to its semi-transparent dial and luminous displays.
This chronograph is the fourth model of the “Lumen” series that A. Lange & Söhne launched in 2010.
What strikes the eye at first sight of the Datograph Up/Down is its vibrant and yet harmoniously balanced dial design. The characteristic outsize-date display in the framed double aperture marks the tip of an equilateral triangle. Its baseline is defined by the two subsidiary dials for the seconds and the precisely jumping minute counter. In the Datograph Up/Down Lumen, the ingenious configuration unfolds a new aesthetic dimension as soon as darkness sets in.
Like mentioned above, this is achieved with a semi-transparent dial and a luminous compound that causes all displays to glow in the darkness – with a distinctive green hue that the human eye perceives as particularly pleasant. The hour and minute hands are filled with the luminous material; the chronograph sweep seconds hand is fully coated with the compound. The seconds hand and minute counter in blued steel revolve above subsidiary dials that are noctilucent, too. The circumferential dial ring with the minute scale that is subdivided into fifth-of-a-second graduations, the concentric tachometer scale and the power-reserve arrow applique also glow in green.
The outsize date is also luminous. composed of two separate display elements, the outsize date is designed to glow immediately after the midnight switching sequence 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. This is enabled by the semi-transparent dial; its coating not only assures crisp legibility in daylight but also allows the luminous compound on the tens cross to be recharged.
The flyback function of the chronograph allows consecutive measurements: an ongoing measurement can be interrupted and a new one started instantaneously with a single touch of the button at 4 o’clock. this rare function saves two steps and therefore time.
The precisely jumping minute counter of the chronograph advances by one marker exactly when the chronograph sweep-seconds hand passes the 60th second, even if the time measurement is stopped at that very moment.
The sapphire-crystal caseback of the 41-mm-platinum case exposes the beauty of the manually wound calibre L951.7. The balance wheel beats at a frequency of 18,000 semi-oscillations per hour, allowing time measurements with a resolution of one-fifth of a second.
The Datograph Up/Down Lumen is limited to 200 pieces and is worn on a black alligator leather strap.