Portugieser Perpetual Calendar Single Moon
This is the latest model of the perpetual calendar, inheriting the Da Vinci design. It features improved shock resistance and, since 2003, the accuracy of the moon phase display has been improved to 1 day every 577.5 years. Reference number IW503302. Automatic winding (Cal. 52610). 54 jewels. 28,800 vph. Power reserve approximately 7 days. 18KRG (diameter 44.2mm). Water resistant to 3 bar. Price: 437 million yen.
This is the latest model of the perpetual calendar, inheriting the Da Vinci design. It features improved shock resistance and, since 2003, the accuracy of the moon phase display has been improved to 1 day every 577.5 years. Reference number IW503302. Automatic winding (Cal. 52610). 54 jewels. 28,800 vph. Power reserve approximately 7 days. 18KRG (diameter 44.2mm). Water resistant to 3 bar. Price: 437 million yen.
Photographs by Masanori Yoshie, Osamu Yajima
Masamasa Hirota, Tetsuo Shinoda, Yukiya Suzuki (this magazine), Masashi Kawai (this magazine): Interviews and writing
Text by Masayuki Hirota, Tetsuo Shinoda, Yukiya Suzuki (Chronos-Japan), Masashi Kawai (Chronos-Japan)
Masamasa Hirota, Tetsuo Shinoda, Yukiya Suzuki (this magazine), Masashi Kawai (this magazine): Interviews and writing
Text by Masayuki Hirota, Tetsuo Shinoda, Yukiya Suzuki (Chronos-Japan), Masashi Kawai (Chronos-Japan)
Pioneer – IWC
The more gears that move the moon phase display, the more accurate the moon phase display will be.
However, this requires space to accommodate an intermediate car for slowing down.
This is why it was once difficult to incorporate a precise moon phase into a wristwatch.
Although theoretically possible, precise display of the moon's age was thought to be impossible in practice.
However, the IWC "Da Vinci Perpetual Calendar" released in 1985,
This has finally become possible, marking the beginning of highly accurate moon phase display.
