Ornatus-Mundi introduces the A. Lange & Söhne Datograph Up/Down Lumen, a limited-edition platinum chronograph that pushes the boundaries of luminous watchmaking. His post highlights the technical ingenuity behind its semi-transparent dial, which ensures all functions, including the outsize date, are visible in darkness, making it a fascinating blend of haute horlogerie and innovative legibility.
Its semitransparent dial allows charging of luminous indices and
complete visibility during night.
This is technically more advanced than
it first appears, as the luminous material is hidden beneath dial
elements. Here an expert from the press info:
"The
“Lumen” version of the DATOGRAPH UP/DOWN makes it possible to use all
chronograph functions even in darkness. Furthermore, the time
indication, the power reserve and even the date are noctilucent. The
technical challenge behind this development was to charge the numerals
of the outsize date with light energy even though some of them are
concealed beneath the dial for the better part of the day.
The
solution is a patented special coating on the semitransparent
sapphire-crystal dial. It filters out most of the visible light, but not
that part of the UV spectrum which is needed to charge the luminous
pigments with enough light energy to keep them glowing uniformly in the
dark. The transmission of light in the visible spectrum is attenuated to
such a degree that, during the day, the sophisticated disc mechanism
and the exquisite finishes are clearly exposed while ensuring good
readability.
Composed
of two separate display elements, the outsize date glows immediately
after the date change at midnight 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. The fascinating
midnight switching sequence can be observed in detail."
Crafted in platinum and limited to 200 pieces.
Magnus
