Recommended Reading: Ming Thein On Lume
And a quick look back at the problem of telling the time at night.
One of the best of simple pleasures in reading about watches (and, I guess, in writing about them too) is encountering a well done lume shot. The art of the lume shot has evolved considerably over the years and everyone who takes a lot of watch pictures, figures out their own way to take them; after starting out many years ago blasting dials with UV light and then taking long exposures in a bathroom with the door shut (which lets the lume show but not the watch, and which looks harsh and unpleasant to boot, as well as exposing you to tasteless japes from your colleagues) I finally figured out that a gentle glow which lets you seen the watch and background, tells you a lot more than just throwing a ton of UV light at a timepiece and hoping for the best.
One of the greatest modern practitioners of the art of the lume shot is Ming Thein, who has made the use of luminous material an intrinsic part of his watch designs ever since the brand launched its first watch – the MING 17.01 – in 2017. His watches are in many respects unique, and he’s doing something which, to this day, relatively few other watch manufacturers or designers are doing, which is to use lume as a part of the design and an essential one, rather than just using it for the pragmatic purpose of nighttime legibility.
In a sense, the problem of telling the time at night is behind the whole enterprise of watch and clockmaking. The first European mechanical clocks, as well as the water clocks before them, appear from the scant records we have from the late Middle Ages, to have told the time by tolling the time – these early clocks would ring the hours rather than show the time on the dial, and the word “clock” may have been derived from the Medieval Latin “clocca” – a bell. (This is a very, very drastic oversimplification of the history of clocks and watches in the Middle Ages, and omits the highly complex water clocks that were made in the same period in the Islamic world and in China, but in broad strokes, that was the picture in Europe, where clocks were fixtures in monasteries, where they’d be used to make sure that monks went to prayers on time).
The sundial is as precise as the Sun, but if it’s raining or nighttime, and town and city tower clocks tolling the time became essential for regulating daily life. Repeaters put audible time in the pocket and made it portable, and then, clocks and watches were made visible at night at last by the invention of luminous materials – at first, radium, which proved hazardous and sometimes deadly, and then tritium, which was less dangerously radioactive but which also had a very short half life, making tritium dials unreadable at night after several years had passed (the half life of tritium is about 12.33 years).
The era of modern luminous dials and hands began with the invention, in 1993, of LumiNova by the Japanese firm Nemoto, and LumiNova, which is based on strontium aluminate, rapidly replaced tritium and is now ubiquitous on watch hands and dials. It is non-radioactive, never wears out (as far as we can tell from 30 years of use) and the most commonly used form, Super-LumiNova, can provide almost an entire night’s visibility depending on the amount used. The only disadvantage to SLN is that it has to be “charged” by exposure to light in order to glow. And increasingly, the stability, safety, and ubiquity of SLN means it can be used for both legibility and visual effects (the Lange Zeitwerk Lumen is an excellent case in point).
One major feature of SLN, however, is that it is not just a single material or a single type of paint. The basic luminous material can be used in a variety of materials and a variety of paints, fillers, and other compounds, and in a recent blog post, Ming Thein goes into the fascinating details of how these materials are used on watch dials, hands, and even crystals and movement components, in order to enhance legibility and create various visual effects. You’ll also find out about why and how different formulations have different colors and you’ll be introduced to the four main methods of applying SLN.
If you’ve ever wondered exactly why some watches glow like a supernova for a good chunk of the night, while others can barely muster a feeble, ghostly gleam, check out Ming’s article, “Design Brief Ch. 8: Understanding Luminous Material.“