Lume or Luminescence, whatever you like to call it, refers to the amazing afterglow in a watch after the lights go off. Enthusiasts and collectors might take this fantastic feature for granted today, but there was a time when luxury watches with luminous properties were a farfetched dream.
Thanks to the invention of luminous paint in the 1900s, watches could finally glow! While many luxury watch brands emit their own light from the beginning of the 20th century, Rolex and Tudor are the best. You can easily determine the era of a luxury watch by checking if it has any luminous material. Watch luminescence which is popularly referred to as ‘lume’ has evolved only over the last century.
So, if you’re interested to know everything about the evolution of lume, this article aims to cover it all!
Phosphors are substances that absorb energy from other sources and emit the energy in the form of visible light. When the phosphor gets its energy from radioactive substances, the light it radiates is known as Radioluminescence.
In the 1900s, watchmakers started applying self-luminous paint with radium and zinc sulfide on the watch dials. Later on, knowing the toxic effects of radium, they stopped the usage of radium on watch dials in 1968. And then came in tritium!
If you come across a watch from that era (1910-1960), some of them have a coat of radium-based luminescence elements. For example, suppose you own a Vintage Rolex Explorer 6610 or a GMT-Master 6542 and wish to sell your Rolex today. In that case, a watch buyer can identify the presence of radium-based luminescence particles.
While tritium also emits radioactive elements, its effect is significantly less than radium. From the onset of the 1960s, watch manufacturers began using tritium-based luminous paints that resulted in the glowing of the watch dials. Some popular watch models include the Rolex Sea-Dweller Ref. 16660 or the Explorer II Ref. 1655.
In 1993, a Japanese company named Nemoto & Co invented a special substance known as LumiNova paint based on a photoluminescent substance. Photoluminescence is the ability of materials to emit light by using light as the energy source. LumiNova, based on the chemical element strontium aluminate, is non-toxic with no radioactive effects. All it needed was exposure to light and post that it would continue to glow after removing the light source. So, in short, LumiNova was the safest luminous material for designing the watch parts.
In 1998, Super-LumiNova came into existence when Nemoto & Co. joined hands with Swiss RC-Tritec AG to create and supply Super-LumiNova to the various Swiss watch manufacturers. Most luxury Swiss watchmakers use Super-LumiNova to curate their timepieces, including Rolex, which started LumiNova in 1998 and Super-LumiNova around 2000.
FYI: Rolex watches with ‘SWISS’ come with LumiNova, while those with ‘SWISS MADE’ come with Super-LumiNova.
It might hit your mind why we are mentioning Rolex now and then. In 2008, Rolex furnished a Deepsea watch with the new form of lume called a Chromalight Display.
Unlike Super-LumiNova, which used to glow green in the dark, the Chromalight display glows blue, which according to the brand, is long-lasting than the others. Soon enough, Rolex started rolling out Chromalight display to the other models and even tried their hands on mixing luminous blue parts with green for a few models.
Other Lume Types
Even though tritium, radium, and LumiNova lumes are the most popular, there are other types worth noting! For instance, some watch brands use small glass tubes filled with tritium gas. This self-luminous element doesn’t require light and needs replacing after approximately 12.5 years.
Others use electroluminescence to glow. As the name implies, electroluminescence needs a current of electricity so that the phosphor can glow.
Now, let’s answer some of the most interesting questions.
How important is Watch Lume?
Honestly, the answer to this question depends on your needs. In certain cases, a good lume might be extremely important to you and in others, not at all! For example, if you’re going for a dive, having lume on your watch is highly important as it will allow you to read the time underwater. In another situation, if you’re going out for lunch or dinner, lume may not be important.
As different watches have different purposes, it is up to you to decide and choose the factor of ‘Lume’. Just remember that a watch lume should fulfil two characteristics:
· It should glow brightly
· It should glow for a longer time
How long does the Watch Lume last?
That depends on the luminous material and the quantity applied to the watch. Most watches today do not use harmful radioactive lume. The tritium lume, which came after that, is a radioactive material that glows consistently for 25 years before it finally becomes weak, making it hard to see.
Most watches, when fully charged, glow the brightest for 4-12 hours before the luminous glow fades, although not all of it. So, the most reliable lume type is the Tritium with a longer-lasting time frame. However, most watch brands have now restricted using the same for safety reasons.
Do all watches have Lume?
Well, most watches today use lume in some way or the other. While some choose to apply luminous materials on both the dial markers and hands, others have it on the hands. Also, there are watches with no lume. A common example of the latter is dress watches. Since these watches do not have the innate need to be precisely functional, some brands choose to omit lume.
How to make the Watch Lume brighter & stronger?
Do you already have a watch with lume and want to know the best way to make it brighter? The solution is quite simple. Simply use a UV torch on it! This will charge the luminescence and allow the lume to glow strongly and brightly. However, this doesn’t apply to the tritium lume timepieces as they do not charge by light!
The evolution of luminous materials is perhaps one of the most essential attributes of watchmaking. After all, to be able to read a watch when the light is low is a boon, even if we somehow take it for granted today!
If you’re looking to get your hands on a luxury watch that satisfies your glowing desires, we suggest Rolex! Whether your taste is conventional or eccentric, Rolex has something to meet all preferences and tastes. Also, the popularity of Rolex watches is so high in the market that the watches make for a popular investment option fetching high value when you sell Rolex in the future.
We admit to being a little biased towards Rolex, and for good!