Nearly twenty years since the debut of the original Datograph in the 1990's, german watch-brand A. Lange & Söhne presents the new Datograph Up/Down “Lumen” - a reinterpretation of the highly precise stopwatch.

The sapphire crystal dial comes with a patented, semitransparent coating which filters out all visible light while concealing the inner workings of the watch at the same time. This coating is permeable to energy-rich UV light which charges the luminous pigments making it easier to operate the timepiece even in the dark.

Composed of a total of 454 parts, the chronograph features a jumping minute counter and a stop mechanism with a flyback function. This allows the wearer to stop an ongoing measurement, reset the hands to zero, and start a new measurement. The watch also displays an Up/Down indication which showcases the state of the wind within the range of the 60-hour power reserve. The hand of the indication is position at the 6 o'clock position in a small display.

The 41mm platinum-case watch comes equipped with the manually wound calibre L951.7 consisting of Lange’s proprietary cam-poised balance wheel, paired with a freely oscillating Lange hairspring, and beats at a frequency of 18,000 semi-oscillations per hour (2.5 hertz). The fourth model in the “Lumen” series, the highlight of the Datograph is the luminous outsize date display. This is made of two separate display elements – a luminous tens cross and a black printed units disc made of transparent glass rotating on a luminous background. The date is designed to glow immediately after the midnight switching sequence.

Presented on a a black alligator leather strap with a platinum prong buckle, the Datograph Up/Down “Lumen” is limited to 200 pieces.