German watchmaker A. Lange & Söhne has launched a limited edition, Datograph Up/Down “Lumen” which is capable of showing time even in darkness, thanks to its semi-transparent dial and luminous displays.
What strikes the eye at first sight of the Datograph Up/Down is its vibrant 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.
The first ever noctilucent chronograph by Lange, the outstanding luminosity 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 minute scale, subdivided into fifth-of-a-second graduations, the concentric tachymeter scale and power-reserve arrow applique also glow in bright green.
But the real stunner is the luminous outsize date. 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. Both elements must be able to recharge during the day when they are positioned beneath the dial. When exposed to light, the entire mechanism is clearly visible. The switching action of the date display at midnight can be observed in detail.
