Watch illumination – The good, the bad and why we use the best

What is Tritium illumination? Tritium illumination is the use of gaseous tritium, a radioactive isotope of hydrogen, to create visible light.

Tritium illumination is widely regarded as the best form of watch illumination due to its self-powered constant glow that it emits throughout the night.

Having the ability to tell the time with ease in the dark is very often overlooked when looking to purchase a watch. However, this ability, of always being able to tell the time no matter what the conditions, is always highly valued in the customers day to day life. This is the reason why each and every Nite watch is fitted with Tritium illumination - the very best form of watch illumination available.

Lots of watches use illumination in one form or another so stay tuned for our insight into the world of watch illumination.



Super-LumiNova is one of the most popular forms of watch illumination and possibly the one that you are most familiar with.

The way it works is where light (artificial or sunlight) charges the paint and afterwards the light is emitted. The charging process can be repeated time and time again. It takes approximately 30 minutes of full sun light to charge a Super- LumiNova dial. We know our community are far too busy making the most of every moment to worry about things like that and that’s one key reason why we stand by Tritium illumination – But we’ll get to that later.


Radium Paint | Ready to turn back time?

Radium dials are dials painted with radioluminescent paint containing radium-226. Radium dial production was at its peek in the first decade of the 20th century as radiation poisoning at that point was unknown. As a result, radium dials have largely been replaced with alternative illumination sources.

Their luminosity is powered from radioactivity. Old radium paint no longer glows in the dark because the radiation burns out the fluorescent material over a short time. Approximately 5 years to be exact. However, the radium remains almost as radioactive as when the paint was brand new!

We’ve included Radium paint in this article because it is very much in watch illumination history and still remains prominent on the pre loved watch market. For safety reasons alone it is quite clear radium paint is one to stay away from.



Electro-luminescent , usually works off a push in button on the side of the watch and is often referred to as EL. Auto EL is a function that will automatically turn on the EL when you tilt your wrist 40 degrees or more. After-glow allows the light to stay on for a short time after it first turns on.

The EL panel should last about 100 hours at least, and if you use the EL for an average of 20 seconds a day then that is just a little over 2 hours per year so it should then last for over 50 years.

Electroluminescence is one of the few instances in which a direct conversion of electric energy into visible light takes place without the generation of heat. EL uses a lot more energy than an LED so you can easily drain the watch battery by pressing the illumination button repeatedly.

A notable downside here is while you’re off having your adventure whether that’s swimming, cycling, hiking or whatever else you would have to stop what you’re doing to push the button on the side of your watch, catch the light while it is still illuminating the watch face, before continuing with what you were doing.


LED light/Digital illumination

The LED watch is one of the styles that is normally called a "digital" watch.

So, how does the illumination work? Rather than using hands and painted-on numbers to tell the time, the LED watch uses tiny light nodes ("light emitting diodes," or "LEDs") to generate light. Whatever the time is, the diodes light up to present that time.

LED watches were the first watches to electronically display the time in a digital format, the first digital watches being mechanical digital watches. The first LED watch was also the first watch in the world without any moving parts.

Digital watches are less durable and refined due to the plastic materials used in their production process. Typically, due to the constraints with the technology, watches using digital illumination will have a certain look and design which isn’t to everyone’s taste.

A plus is that they can give time accurately and very easily at once glance. However, overall, If you’re looking for a stand out watch to wear with pride, a digital watch may be one to miss.




Tritium Illumination | Our time to shine!

The Tritium illumination used in all Nite watches is supplied by mb-microtec of Switzerland. We offer both T25 and T100 rated watches to allow our customers to choose whichever works best for their lifestyle. Whether bright light is essential to your day to day activities or you just need light to guide you, you’ll find the right light for you. If you wake up in the night and want to know the time or are coming back late from a hike you will have the light you need at your fingertips – literally!

Now, time for the technical bit. Tritium emits electrons through beta decay and when these electrons interact with a phosphorous material, a fluorescent light is created that can last up to 20 years.

When this Tritium powered illumination is sealed inside a glass tube, it is known as a GTLS (Gaseous Tritium Light Source) To produce a GTLS vial, glass is lined with phosphorescent material, then filled and pressurised by a machine with gaseous Tritium and sliced into segments by a laser beam to be sealed in a way that is completely airtight.

Inside the vial, the electrons emitted by the Tritium gas excites the phosphor which is a chemical compound that emits light when it is exposed to light of a different wavelength to in turn give off the cold continuous light.

The benefit of all this technology is that you have a watch with self-powered illumination providing you with a constant glow throughout the night, whatever the conditions.

So no matter if you are out on a critical mission, hiking through the night or simply glancing at the time on your bedside table, you can be sure that you will easily be able to tell the time in an instance.


In our humble opinion, Tritium illumination provides the perfect balance between visibility, performance and design.

This is why we are proud to use Swiss made Tritium illumination supplied by mb-microtec of Switzerland - the original founders and market leaders of the technology in every Nite watch.

If you ever have any other questions about Tritium or our watches please send us an email to where we would be happy to help.

In the meantime, why not take a look at our collection of Tritium watches.