ALL ABOUT: Luminescence – Clash of Brands

Tags: Technology and concepts | Classic

20.7.2022 | 8 MIN

In today's episode of "All About", we've decided to cover watch luminescence and test it thoroughly for the real life. Is there a difference between the Swiss Super-LumiNova and LumiBrite by Seiko? And how does the Invicta's Tritnite compare to them? And what about Casio's Neobrite or the unknown luminescence brand of Diesel's fashion watches? Overall – how will they stand next to each other? We can say that the results were shocking.

This article discusses mainly the practical feature of luminescence. If you'd like to know more about the (dreadful) back story and how the names of luminescence were created, our colleague Radim wrote about these:

Contents:

• Types of luminescence
• Test – Participants and expectations
• Test – Results

What types of luminescence exist?

We need to tell the time even at night or in the dark. That's why many ways to light up your watch came into existence. To put it shortly – types of luminescence are distinguished by the source of the light: photoluminescence, radioluminescence, and electroluminescence.

Electroluminescence

Electroluminescence usually lights up the whole display (or dial, as it is with the Indiglo luminescence by Timex), and it appears in quartz watches only. We will not be testing this type of luminescence in our practical test.

The Timex electroluminescence Indiglo.

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Photoluminescence

However, we will be discussing photoluminescence, which is the most common kind in watches. It is a luminescent coating which we can usually find on hands and indices, but also on the bezel or the whole area of the dial. What activates photoluminescence is a source of ultraviolet rays or visible light – it is therefore necessary to "charge it" with light.

The coating might have more than one layer – the more luminescent material, the brighter the glow. What is also true is that luminescence of the same brand might give out various levels of brightness as different types of watches demand different brightness (e. g. a dive watch needs much more bright luminescence than other kinds of watches).

A typical example of photoluminescence.

Both Sun light and artificial light are suitable for "charging", but many watch enthusiasts say that one can get the best result using natural light. When the energy from the light lands on the luminescent material, electrons get all excited and start emitting light. As the energy levels of electrons go down, so does the brightness of luminescence. However, one of the advantages of photoluminescence is that the material doesn't get old and shines repeatedly.

There are many names on the market for photoluminescence. The most known is the Super-LumiNova, which is usually used by Swiss brands, the Japanese LumiBrite (with Seiko and allegedly other associated brands like Pulsar or Lorus, Invicta's Tritnite, Chromalight by Rolex, Natulight by Citizen, Neobrite by Casio, and many more. Many watchmaking brands, usually those that offer affordable or fashionable watches, do not even state the name of their luminescence.

All this leads to discussions between fans who argue which brand luminescence lasts longer and what the differences even are. And this is exactly the topic of today's article.

Radioluminescence

The third type is radioluminescence. Radioactive, but completely safe today, luminescence is based on Tritium gas filling small, hermetic, glass tubes.

A typical example of radioluminescence.

Because of a reaction, radioluminescence is a steady light without the need to be charged by another light source. This is very different from watches employing photoluminescence, which require being exposed to an external source, and as the brightness starts fading after some time. In comparison, the self-powered micro gas light tubes shine steadily, with the life expectancy up to 25 years. However, the material gives out after some time and cannot be restored. Radioluminescence is used by brands such as Luminox, Traser, and Ball.

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Out of curiosity, we put a Ball watch combining radioluminescence (hands, indices), and photoluminescence (Super-LumiNova on the bezel) against other watches employing photoluminescence.

Luminescence comes in different colour variation, but the most used ones are green, yellow-green, and blue, which is because of the way our eyes interpret brightness as colours – we simply perceive these colours as the brightest.

Luminescence "battle" – Who are the participants and what are the expectations?

We've decided to do this test in the form of a time lapse. We chose 10 watches (due to capacity reasons, otherwise we would test much more – in the future, we certainly plan to do "wars of light" between different and most interesting pieces we have). For the purpose of this first battle and article of this sort, we chose watches to represent different brands and types of luminescence. This battle is supposed to demonstrate the information we have and whether our expectations were met, or to show any surprises, whether bad or pleasant...

The watches were equally exposed to direct sun light for a whole hour, which is even much more than they are supposed to need to light up. However, keep in mind that camera distorts pictures and cannot be even compared to human eye. Eyes adjusted to dark should be able to see the luminescence of watches for several hours, but cameras on the other hand... After 3 hours, it was practically useless to keep filming. But for our purposes it was enough.

Super-LumiNova

As representants of the Swiss Super-LumiNova, we chose:

The Certina DS-8 – formal watch, where one doesn't necessarily require bright luminescence (some people even perceive luminescence in formal watches as inappropriate, no matter how decent).

The Edox Skydiver Neptunian – a dive watch with Super-LumiNova X1, which is the highest level, therefore naturally with the highest expectations.

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The Tissot Seastar 1000 Chronograph – Tissot does not state the brightness of its luminescence, so, this was more of a test to show what level of Super-LumiNova we can expect from the basic quartz Seastar 1000, how it will compare to the Skydiver, and if it will be better than the formal Certina.

Super-LumiNova is also present on the bezel of the Ball Roadmaster Marine, but I also wasn't able to find out the luminosity.

There are three levels of Super-LumiNova: Standard (lowest), Grade A (a middle ground), and Grade X1 (highest). Grade X1 is the latest level, and according to the RC Tritec company, it shows an improvement in glow of up to 60 % after two hours in comparison with the Standard Grade. What is however not stated is the improvement of Grade X1 in comparison with Grade A.

LumiBrite

Japanese LumiBrite seems like a very fascinating type of luminescence, it is used by Seiko and (allegedly) other brands that are part of it. For this test, we chose the dive model of the Prospex line, a basic quartz chronograph, and a similar quartz model by Pulsar (which does not state details about the luminescence, and only non-reliable sources say that this watch uses LumiBrite, so, this test is to verify that):

The dive watch Seiko Prospex Sea SPB189J1, also called "Shogun", about which we have great expectations.

The basic chronograph quartz model Seiko Chronograph Titanium Quartz SSB391P1.

The solar Pulsar Accelerator Solar Chronograph PZ5110X1 by Pulsar, which is a division of Seiko. Is the luminescence comparable with the basic Seiko model?

LumiBrite prides itself on illuminating hands and indices for three to five hours after ten minutes in the sun light.

Tritnite

Not once were we surprised by the quality of characteristic Invicta. However, the reputation of the Tritnite luminescence, used only by Invicta, is quite poor (maybe that's the reason why Invicta sometimes chooses to use Super-LumiNova). Naturally, we don't expect much from the Invicta Pro Diver Automatic 0420.

All the watches are given the same conditions – and hour-long exposure to the sunlight, which, as I said, should be more than enough... but after digging a bit deeper into this topic, I stumbled upon a tiny little note in an Invicta manual: "Tritnite requires 4-5 hours of exposure to light for it to glow brightly in the dark. It will continue to perform with regular exposure to light." Therefore, Tritnite did not have its required conditions, so I made a mental note to give it another chance for the next article.

Neobrite

Casio's Neobrite is one big mystery; Sherlock himself would have troubles finding information about it. I'm eager to find out the results of today to get to know it better. That being said, Casio is an affordable brand, and from experience, the luminescence is no star. But we will see...

A representant of Neobrite is the popular Casio Edifice ECB-900DB-1AER, which were put next to other brands' quartz chronographs for comparison.

Fashionable anonymous luminescence

For comparison (and out of curiosity), we also chose the fashionable quartz chronograph Diesel Mega Chief, which is quite popular with men. And who knows, maybe we will be nicely surprised.

And the winner is ... – Were our expectations correct?

How did the battle go? Here's a sped-up video:

Let's celebrate and have a feast – the winner was who we expected: Seiko Prospex Sea with LumiBrite! (Yes, Agáta, you were right ;))

Agáta – our Seiko master, who knew the winner all along. Check out her articles.

Speaking of LumiBrite, the Seiko Quartz Chronograph and Pulsar Accelerator were not bad either.

Minute 123: Pulsar was still gently, yet bravely glowing, while Seiko Quartz Chronograph was shining till the end, although much less than its big diver bro. It got its deserved third place!

When it came to Swiss Super-LumiNova, it was quite a surprise. Although we were completely sure that the Edox with the glorified Grade X1 will crush the rest of the contestants, and we just wanted to compare it to the Tissot Seastar to check whether the brightness is the same, we can see that the Edox was giving up and lost a lot of its brightness around the minute 102 (going dark at 126^th minute).

Meanwhile the Seastar was crushing the other watches – the watch even got its second place and came within a hair's breadth of the gold medal (Seiko was glowing a bit more towards the end).

Minute 102: The Edox Skydiver has gone completely dark soon to our surprise. Maybe the piece we picked was not very good. For the next test, we're going to pick a different model with the same type of luminescence.

The formal Certina was glowing ever so slightly till the end, and the bezel of the Ball went dark (for our camera lens) around the minute 162.

Tritnite by Invicta suffered bitter defeat and stopped glowing at 57^th minute.

And the affordable Casio's Neobrite? It didn't do bad. Around the minute 111, it was glowing more than the Pulsar watch and, surprisingly, equally as the Edox Skydiver. And it managed to do so a bit longer, till the minute 130.

The fashionable Diesel lasted around 60 minutes, which is itty bitty longer than Invicta's Tritnite. But as I said above, we have to test Invicta one more time.

And that's all for today's battle. Congratulations to Seiko, and let us know in the comments what other watches you want us to test in the next episodes! :)

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