A. Lange & Söhne's latest masterpiece for 2026 is the Lange 1 Tourbillon Perpetual Calendar Lumen, a limited edition of 50 pieces. This watch brilliantly combines two of the brand’s most complex complications – the tourbillon and the perpetual calendar – with its innovative Lumen technology, marking a significant advancement. While retaining the distinctive off-centred design and classic proportions of the iconic Lange 1, this timepiece is driven by a sophisticated new calibre, the L225.1. The semi-transparent sapphire dial offers a captivating view of the meticulously finished internal mechanisms, which, when in low light, emit a striking green luminescence, enhancing the watch's indications with an otherworldly glow. This fusion of mechanical ingenuity and luminous display sets a new benchmark for horological artistry.

The creation of the Lange 1 Tourbillon Perpetual Calendar Lumen represents a pinnacle of A. Lange & Söhne's mechanical expertise, bringing together two cornerstones of the Saxon manufacture's legacy: the acclaimed Lange 1 Tourbillon Perpetual Calendar and the groundbreaking Lumen concept. The narrative of the Lange 1 began in 1994, when Günter Blümlein and Walter Lange embarked on the ambitious revival of the brand. Their goal was to produce a watch that would encapsulate the historical essence and future direction of A. Lange & Söhne. The Lange 1, with its innovative asymmetric layout and distinctive outsize date display, quickly became the brand's quintessential emblem, part of the initial four watches introduced at its rebirth.

In 2012, the Lange 1 series saw a significant enhancement with the introduction of a tourbillon and a perpetual calendar. Integrating these complex features into the Lange 1's unique asymmetric dial presented considerable engineering challenges. Lange's artisans devised ingenious solutions, such as a peripheral month ring indicated by a pointer at 6 o'clock, a retrograde day of the week indicator gracefully arching on the dial's left side, and moon phases sharing space with the small seconds. The tourbillon, a marvel of precision, was discreetly positioned on the reverse side of the watch. For fourteen years, the Lange 1 Tourbillon Perpetual Calendar models were consistently powered by the automatic calibre L082.1. This movement featured a fully integrated perpetual calendar, built around the tourbillon, and included the brand's patented stop-seconds mechanism, along with a 21k yellow gold rotor with a platinum mass. Its dimensions, 41.9mm in diameter and 12.2mm thick, and its intricate layout remained unchanged throughout this period.

The second pivotal element, Lange's "Lumen" technology, originated from Director of Product Development Anthony de Haas's frustration with the poor legibility of his platinum Zeitwerk in the dark. The solution involved applying a luminescent material to the jumping numeral discs. However, their rapid movement necessitated a novel charging method. This led to the development of a tinted, semi-transparent sapphire dial that filters most visible light but allows ultraviolet light to pass through, effectively charging the hidden discs beneath. This innovative system ensures that the numerals faintly glow beneath the surface, then illuminate with full intensity the moment they jump into view. First appearing on the Zeitwerk 'Luminous' in 2010, this patented mechanism established the foundation for what would become the esteemed “Lumen” collection.

The fusion of the Lange 1 Tourbillon Perpetual Calendar with the "Lumen" concept imbues the watch with a novel character. In daylight, the semi-transparent sapphire, with its dark tint, permits UV rays to energize the various display mechanisms, revealing an array of meticulously crafted components. These include large plates adorned with perlage, levers with straight graining, precisely cut toothed wheels, and chamfered edges. However, in darkness, the Lumen technology transforms the watch, casting an enthralling green luminescence. This glow dramatically enhances the visibility of the two numerals in the outsize date window. Furthermore, the moon phase display is now luminescent, featuring an integrated day/night indicator, and the celestial backdrop accompanying the moon’s precise cycles is adorned with countless glowing stars. Beyond the illuminated date aperture, the leap year display is also coated with a luminescent compound, as are the hour and minute hands, the retrograde jumping weekday hand, and the small seconds hand, creating a truly spectacular nocturnal display.

The new Calibre L225.1 represents a significant leap in complexity compared to its predecessor, boasting 685 parts versus approximately 500, and 74 jewels compared to around 62. Power is generated by an 18k white gold rotor with a platinum centrifugal mass, providing a robust 50-hour power reserve. This movement is meticulously decorated with the A. Lange & Söhne signature in relief. The one-minute tourbillon, secured by a diamond endstone in a screwed gold chaton, pays homage to Lange’s historic pocket watches. Coupled with an in-house balance spring, the tourbillon ensures exceptional rate accuracy for the movement, which operates at 21,600 vibrations per hour. A stop-seconds device, activated by the crown, halts the balance for precise one-second adjustments. All calendar indications switch instantaneously and can be adjusted collectively or individually using the case correctors. Assuming continuous operation, the calendar indications will not require adjustment until March 1, 2100, and the moon phase cycle will only need correction after 122.6 years.

The timepiece is encased in a 41.9mm diameter, 13mm thick platinum case, showcasing gleaming polished surfaces contrasting with a brushed case middle. It is complemented by an elegant black alligator leather strap featuring a deployant quick-lock platinum buckle. This exclusive model is part of a limited edition of 50 watches, with the pricing available upon direct inquiry, as is customary for Lange's prestigious offerings.