Sarpaneva Lunations is the very first Sarpaneva watch to house an ultra-precise integrated phases of the moon calibre that distils all 25 years of Stepan Sarpaneva’s professional watchmaking expertise. The lunation in the aptly named Sarpaneva Moonment® in-house calibre lasts 29 days, 12 hours, 44 minutes and 2.3 seconds, which means it needs to be adjusted for a single day of error only once every 14,000 years.
A large moon aperture at 6 o’clock is filled with a cross section of optical fibre, which runs throughout the entire height of the movement. A disc inset with RC Tritec’s Lumicast® represents the moon and rotates excentrically on the reverse of the movement. The phase of the moon is thus indicated by the section of the moon disc visible through the optical fibre aperture. Sarpaneva’s signature moon face has been reproduced by laser-engraving the optical fibre, which is then hand-finished by traditional polishing techniques with diamond paste and a pegwood tool.
Not only is Sarpaneva Lunations uniquely precise in its display, it is also uniquely precise in the way it is set. Pulling the crown at 4 o’clock out to the first position allows the wearer to set the phases of the moon display. An integrated phases of the moon scale, engraved on the back of the watch, and the Sarpaneva Moon mobile app provide additional guidance on getting the display as close to the actual lunar cycle as possible.
Sarpaneva Lunations can also be easily customised to reflect the lunar cycle in both northern and southern hemispheres.