On the occasion of Watches & Wonders Geneva 2026, which opens today, A. Lange & Söhne unveils the Lange 1 Tourbillon Perpetual Calendar Lumen, a limited edition combining a tourbillon with stop-seconds and a perpetual calendar with a peripheral month ring and instantaneous switching displays.
All indications remain legible in the dark, in line with the concept of Lange’s “Lumen” models, thanks to the use of luminous elements of varying intensity.
Housed in a 41.9 mm case with a thickness of 13 mm, crafted from 950 platinum, the Lange 1 Tourbillon Perpetual Calendar Lumen retains the characteristic off-centre dial layout, with the centres of the subsidiary seconds dial, the main dial and the outsize-date display positioned at the corners of an imaginary isosceles triangle.
The months are indicated on a rotating circumferential ring, while the leap-year display is positioned in a small aperture at 6 o’clock.
All calendar indications switch instantaneously, ensuring precise readings. The indications can be adjusted either collectively or individually via correctors on the case. When running continuously, the calendar will require correction for the first time on 1 March 2100.
The hands and applied indices in rhodiumed gold stand out clearly against the dark background, with Super-LumiNova applied to the hands.
The semi-transparent dial allows UV light to pass through, continuously charging the luminous material of the underlying displays.
The outsize date, composed of a tens cross and units disc, is fully visible in the dark. The watch also introduces a luminous moon-phase display combined with a day/night indication.
A celestial disc rotates once every 24 hours, showing a light sky during the day and a darker sky with luminous stars at night. The display deviates from the actual lunar cycle by one day after 122.6 years.
The leap-year display at 6 o’clock is also luminescent, matching the visual intensity of the outsize date, while the other indications, including hours, minutes, seconds and day of the week, are rendered with more restrained luminosity.
The semi-transparent dial also reveals parts of the movement, including plates decorated with perlage, bridges with solarisation, levers with straight graining and wheels with circular graining.
The tourbillon itself is not visible from the dial side and is revealed through the sapphire crystal caseback. The carriage rotates once per minute to counteract the effects of gravity on the balance.
The Lange manufacture L225.1 movement operates at a frequency of 3 Hz (21,600 vibrations per hour) and incorporates an in-house balance spring.
A stop-seconds mechanism allows the balance within the tourbillon cage to be halted when the crown is pulled, enabling precise time setting. This system is based on a patented construction introduced by the manufacture in 2008.
Particular attention is given to the finishing of the tourbillon cage, as well as the tourbillon cock and intermediate-wheel cock, all crafted from stainless steel.
These components feature black polishing, achieved by carefully sliding the parts by hand across a tin plate with abrasive paste until a perfectly smooth surface is obtained. Depending on the angle of the light, the finish appears either mirror-like or deep black.
All edges are chamfered and polished, with internal angles requiring especially precise manual work.
The movement is fitted with a central rotor, crafted from 18-carat white gold for the first time, ensuring efficient winding. An external mass in 950 platinum increases inertia, allowing the watch to reach its maximum power reserve of 50 hours after relatively short wear.
The rotor contrasts a dark, black-rhodiumed central section with a lighter platinum outer ring.
The tourbillon cock and intermediate-wheel cock are further decorated with hand-engraved star motifs, later polished to stand out against the matte surfaces.
At the centre of the tourbillon, a diamond endstone set in a screwed gold chaton recalls traditional finishing elements used in high-grade pocket watches.
Paired with a black alligator leather strap and a deployant quick-lock buckle in 950 platinum, the A. Lange & Söhne Lange 1 Tourbillon Perpetual Calendar Lumen, ref. 720.035FE, is issued in a limited edition of 50 pieces. Price is available on request. alange-soehne.com
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