« Luxury Watches in the Dark Are Beauties of the Night »
By day, a wristwatch has plenty of ways to impress – whether through the design of its case and bracelet, the styling of its dial or elaborate complications. Once darkness falls, however, little of all that remains visible. While some watches all but disappear, others still let you read the time thanks to luminous hands and indices. And a few models captivate with a particularly beautiful glow. We took a closer look at some especially attractive beauties of the night from brands such as Breitling, Omega, Rolex and TAG Heuer.
What Exactly Does "Luminous Watch" Mean?
There are indeed some wristwatches fitted with a small lamp to illuminate the dial or with a flashlight function, but such models are rare in the luxury segment and are more often found at retailers of outdoor or camping gear. When people talk about high-end watches with illumination, they usually mean that the hands and indices or the dials are coated with luminous material, so the time can be read easily even in the dark.
Traditionally, luminous hands and indices are found above all on pilot's, dive and military watches. Beyond the purely practical reasons for using hands and indices that glow in the dark, many manufacturers now deliberately exploit the aesthetic appeal that such a dial can unfold at night.
Lume – Originally Developed for Military Use
Luminous paint, or luminous compound, is a material that can emit more visible light than is currently falling on it. This property is known as luminescence, which is reflected, among other things, in the brand names Luminova and Superluminova.
Luminescence is what distinguishes so-called luminous pigments from other, non-luminous color pigments. With a paint containing a sufficient quantity of luminous pigments, coated surfaces glow in the dark. That sets them apart from reflectors, which merely return the light currently striking them. In physical terms, luminescence can be based on different principles.
How Do Luminous Watches Work?
First, there are so-called daylight fluorescent paints. These convert incoming UV light, which the human eye cannot perceive, into visible light. This creates the impression of especially vivid colors.
Typical examples of this effect are the neon colors used for safety vests, warning signs or the markings on emergency vehicles and hazardous-materials transporters. Since these require UV light to strike them, however, they are unsuitable for making watches legible in poor lighting conditions. That calls for so-called phosphorescent paints. These are able to store incoming light in the form of excitation energy and release it again later after a certain delay.
This principle dominates in luminous watches today, but it is also used in practice for other purposes, such as marking emergency exits or producing various glow-in-the-dark decorations and novelty items.
Radioactive Luminous Paints – No Longer a Hazard Today
Finally, the third option is radioactive luminous paint, in which a radioactive and a fluorescent substance are combined. The energy needed for the glow is generated directly or indirectly by the decay of the radioactive substance, which excites the fluorescent substance. Whereas radium salt was primarily used for this purpose in the past, it has since been almost entirely replaced by promethium salt and tritium compounds.
The low-energy beta emitters used today pose no health risk – unlike the radium-based luminous paints common in the past. Their direct radiation has a range of only a few centimeters and is too weak to penetrate the watch's metal case or crystal. Nevertheless, over recent years and decades the non-radioactive phosphorescent paints, known in particular under the brand names Luminova and Superluminova, have increasingly prevailed in the luxury watch segment.
Precisely Legible and Graphically Appealing: The "Second Face" of the Rolex Submariner
Among the luxury watches with the clearest, most distinct "faces" at night is the Rolex Submariner. The elements essential for telling the time are generously coated with blue-glowing Chromalight and sized so that they can be read very easily underwater and at night. The glow easily lasts through an entire night, which, unfortunately, cannot be taken for granted with every luminous watch, even in the luxury segment. Thanks to the distinctive design of the hands and indices, confusion is virtually ruled out.
Twelve o'clock is marked by an inverted triangle, so it is always clear where the top is. Six and nine are represented by a bold bar. All other hours are indicated by a round dot, and only at three o'clock does it stay dark because of the date window located there.
In addition, there is a luminous pip on the bezel, so it can be used in the dark as well – although, of course, individual minutes cannot be read at that point.
Omega's Moonwatch Relies Entirely on Slender Lines
The Omega Speedmaster Professional, which achieved eternal fame as the "Moonwatch," shows that dial details need not look as massive as on the Submariner to remain visible in the dark.
Here, all hour indices glow at night as slender lines, as do the hour and minute hands. The only addition is a pair of small luminous dots flanking the twelve o'clock marker. They ensure the watch isn't accidentally read in the wrong, slightly rotated position – especially when it isn't on your wrist but perhaps lying on the nightstand.
Incidentally, another example of an unmistakable "second face" is Omega's Seamaster Professional. In the dark, its skeleton hands look as if a delicate pair of tweezers made of two lines were holding the dot and the triangle at the tips of the hour and minute hands, respectively.
Beautiful Luminous Watches from TAG Heuer and Breitling
The Breitling Colt 44 is purist yet makes no compromise whatsoever on legibility in the dark. The three-hand watch with date at three o'clock features simple baton indices that are just as easy to see in the dark as the Arabic numerals at six, nine and twelve and the slender hands.
Among TAG Heuer's sporty luminous watches, the Aquaracer collection impressed us most in our night-shot comparison. As on the Submariner, baton indices alternate with pairs of dot indices, but at three o'clock it doesn't stay completely dark: next to the date window, at least a remnant of the baton index you would expect there remains.
TAG Heuer's Formula 1 collection also scores in the dark with high recognizability, an appealing graphic effect and good legibility.
It should not go unmentioned that the ever more varied ways of using lume, which is now available in numerous colors, tempt some manufacturers into especially creative experiments.
You can certainly find watches whose glowing image in the dark looks far more creative than the comparatively purist solutions on the watches presented here. However, this often comes at the expense of unambiguous legibility, which is why we have refrained from including such examples here.
