3478.27 years of precision! Mathematically speaking, Ludwig Oechslin’s moon phase watch incorporates one of the world’s most accurate moon phase indications ever found in a wristwatch. And it’s based on just five components.
If conventional watches do have a moon phase indication, it’s usually tucked away in a small window somewhere on the dial. The ochs und junior moon phase is different – here, the whole dial forms part of the indication: the moon revolves around the centre, which represents Earth. The large dot at 12 o’clock represents the sun.
The indication not only shows the illuminated, visible portion of the moon, but also its current position relative to Earth and the sun.
The titanium disk bearing representations of the moon rotates counterclockwise. On it are two moons: the full moon as a luminescent dot and the new moon as a grey dot. The crescent-shaped aperture in the dial reveals exactly as much of both dots as can be observed of the illuminated and unilluminated portions of the actual moon. In addition, the movement of the luminescent dot traces the orbit of the moon around Earth, and the dot’s position relative to the center and 12 o’clock corresponds to the position of the moon relative to Earth and the sun.
The date indication, as with all of ochs und junior’s timepieces, is intuitive and devoid of any alphanumeric markings. Reading it soon becomes second nature; its visual impact is also less intrusive. Unlike the over-sized date displays found in so many other watches, the hierarchy here is clear: time first, then the date.
The 31 date perforations, arranged as a gentle spiral, are ingeniously aligned with the indices for easy readability. The date is recognized purely by position. Decreasing subtly in length as the spiral progresses, the 10-minute indices mark the 5th, 10th, 15th, 20th, 25th and 30th of the month. The 31st and 1st are in line with each other.
Rotating beneath the perforations to indicate the date is what appears to be an orange dot; it is in fact a curved dash set at a precisely calculated angle. The lower portion of the dash is visible through the '1st' perforation – the upper portion through the '31st'.
The date perforations are each exactly two minutes apart on the dial for added readability of the exact minute and second.
The ochs und junior moon phase represents yet another example of Ludwig Oechslin’s insistence on simplicity, clarity and functionality of design.
Ludwig Oechslin develops his functions from scratch and implements innovative solutions. He is driven by the challenge of displaying a function in a better way than currently available in wristwatches. He instinctively chooses the simplest approach – which leads to radical simplification.
When working on his selene moon phase watch, Oechslin sought utmost precision combined with optimal ease of manufacturing – which meant using as few components as possible.
Here he describes his idea, his solution and his modus operandi:
Description by Ludwig Oechslin:
Task / idea
A wristwatch incorporating a moon phase indication that reflects the lunar cycle as accurately as possible.
Solution / implementation
The sun is represented by a large static dot on the dial at 12 o’clock. The moon appears in a crescent-shaped aperture, which describes an exactly computed arc around the centre of the dial. The widest point of the crescent-shaped aperture is exactly opposite the sun at the 6 o’clock position. Rotating beneath the dial is the lunar disc bearing a full moon and, opposite it, a new moon. As the disc rotates counterclockwise, the crescent shape of the aperture in the dial makes the full and new moons appear to wane as they approach the sun and wax as they move away from it; they are at their most visible at the 6 o’clock position. One complete rotation of the lunar disc therefore represents one lunar cycle with all of the moon’s phases. The lunar disc is driven by an epicyclic or planetary gear mechanism. The epicyclic wheels on the underside of the lunar disc are driven from the centre by a finger bonded directly to the hour pipe, their circumferences meshing with a recessed ring gear machined into the underside of the dial. This turns the lunar disk beneath the dial anticlockwise. The central finger engages with a wheel bearing 12 teeth, whose pinion with 14 teeth meshes with a wheel bearing 18 teeth, whose pinion with 14 teeth meshes with the fixed recessed ring gear with its 109 teeth machined into the underside of the dial. This results in a single rotation of the lunar disc in 29.5306122449 days. This is equivalent to a deviation of one day in 3478.27 years.
A conventional moon phase indication performs one complete rotation in 29.5 days. After two years the deviation here amounts to around one day.
Other more sophisticated moon phase indications implemented in wristwatches deviate by one day after 122, 500 or 1007 years. The ochs und junior moon phase thus represents one of the world’s most mathematically precise moon phase indications – and the one incorporating the fewest components.
In our view, the wristwatch plays an integral, functional role in our lives – and it should be designed accordingly.
Ludwig Oechslin does just that with his watches. The design of his timepieces emerges as a logical consequence of their functions, which makes it distinctive. Most of our timepieces make do without alphanumeric markings of any kind, and that includes any branding or logo.
You won’t find indications of the make and model on an ochs und junior dial, or of the watertightness, precision or country of origin. In fact, there is a logo, but it’s discreetly branded onto the back of the eco-tanned leather strap.
The design of ochs und junior watches is for people who live in the here and now.
Ludwig Oechslin’s guiding principle of functional reductionism is reflected in the mechanics as well as in the appearance of his timepieces. A prototype leaves his private workshop only when he has completed the first stage – incorporating his latest thinking into it.
By assembling the prototypes himself, he proves that they can be produced.
Small numbers of components ingeniously put together are easier to handle at a mechanical level, and thus a better solution in the long term, than one based on as many parts as possible.
Ludwig Oechslin creates and develops the mechanics and makes the initial prototypes.
He then lives with them for some time, carrying them either on his wrist or in a waistcoat pocket. These prototypes don’t have an easy life. They are stressed, handled roughly and subjected to the kind of treatment that our production watches never have to endure.
Talking of production, our approach is as distinctive as our designs and unlike that of any other watch company.
The technical drawings and a prototype are forwarded to Peter Cantieni. His main activity consists of machining ultra-precise titanium components for the Swiss Formula One racing team Sauber. Based in Hinwil, his experience allows him to manufacture most of the minuscule components we need for a pre-production batch of watches.
These components are then brought to master watchmaker Marion Müller. In her workshop in Kappel am Albis, she assembles the initial few watches and corrects various aspects to ensure optimal functionality and ease of assembly when the time comes for the definitive production run. The radical nature of Ludwig Oechslin’s innovative functions remains sacrosanct throughout this process. Marion Müller does not reinterpret them, nor does she attempt to make them more conventional.
After all, experience has shown that the fewer interfaces there are in a mechanical product and in its production process, the greater its reliability and the longer its service life.
Marion Müller’s feedback now helps Peter Cantieni machine the definitive components, including the two-part case, the buckle (carved out of a single block), the functional dial and the wheels. In other words, almost everything we need to create our watches, not counting the movement itself.
Marion Müller then painstakingly assembles the selene and regulates the movement, for which we use the self-winding mechanical ETA 2824-2. We rely on this dependable and highly functional workhorse for most of our watch concepts.
Your ochs und junior moon phase can be customized to your exact specifications (more about this below). However, ochs und junior also offer a special edition which is very close to the original prototype Ludwig Oechslin created in his workshop. This special execution is called “moon phase patina”.
moon phase patina features a high-contrast dial executed entirely in one material, brass. Just two metals are visible on the watch: brass (all dial components including hands) and titanium (case, crown, buckle).
The brass dial is hand-patinated through an antique sculpture restoration process, turning it a dark grey color. Then the indices, date dot, and moon are milled-out to reveal the metal beneath. The hand-satinated brass hour and minute hands are rendered instantly visible by hand-patinating the brass second hand.
The reductionist concept behind moon phase patina’s all-brass dial goes back to Ludwig Oechslin’s workshop. Once Ludwig has finished conceptualizing his latest watch innovation, he begins creating prototypes in his workshop for his own personal use. Legibility, functionality, and contrast are critical to him when designing a new watch. To control the entire process and iterate rapidly, Ludwig uses an antiquing solution to patinate the brass dial and then mills out the features which need to have contrast. This enables him to forgo the additional manufacturing steps of adding color and to quickly test the usability of his designs — without complicating the process.
The production versions of moon phase patina are manufactured by Peter Cantieni in his workshop in Hinwil. Each moon phase patina is a unique piece due to natural differences in the hand-patination and satination processes. You can view additional pictures of moon phase patina in our photo gallery and on our stock page.
When it comes to watches, what is important to you? Optimal readability with maximum contrast? Readability at night?
A black dial with white hands and indices and an orange ‘date dot’? This option would give you the highest contrast and best readability.
Or how about a dark bluish-grey dial, again with white hands and indices? This is currently the most popular ochs und junior option: still offering perfect contrast, it’s a little less ‘hard’ than the black dial. Or maybe a light-colored dial with black hands? … Almost anything is possible!
Our store page shows the watches we have created for immediate delivery. They all meet different wearers’ preferences. These particular watches are available off-the-shelf from Lucerne.
Or would you prefer to choose the colors of the dial, hands and indices? Your personalized watch, tailored to your requirements! That is what we at ochs und junior are uniquely able to offer. A watch to suit your tastes.
The ochs und junior watch visualization technology is where you can test your ideas and email them to us:
We would be delighted to discuss your preferences and ideas via email, telephone or Skype. Or come and see us in Lucerne for an espresso served from our vintage Gaggia. We’ll make sure you get the watch of your dreams.
The watch industry usually offers two years’ guarantee against manufacturing defects. That’s also the case here at ochs und junior.
The following timepieces also benefit from the ochs und junior long-term guarantee: moon phase, annual calendar, date, two time zones.
These watches come with a lifelong guarantee against manufacturing defects affecting the following parts made for ochs und junior by Peter Cantieni:
moon phase (selene)
The watches are functionally extremely reliable thanks to Ludwig Oechslin’s reductionist approach to components. During the periodic service interventions (or during a repair intervention if needed) we can see how the internal works are doing in terms of service life. If our appraisals indicate possible issues, we can immediately revise the parts in question for new batches of watches and, if necessary, replace them in existing watches.
This guarantee also applies retrospectively to all watches in the above series that have already been bought.