Compare the most common watch lume types side by side. See realistic initial brightness, colour, and how long each type stays readable in the dark.
Relative readability (approximate). Higher bar = easier to read.
| Type | Colour | Charge needed | Readable duration |
|---|---|---|---|
| Super-LumiNova C3 | Yellow-green | Yes (light) | Very strong first hours, good for 4–8 h |
| Super-LumiNova BGW9 | Blue-white | Yes (light) | Slightly longer residual glow than C3 |
| Rolex Chromalight | Blue | Yes (light) | Optimised for long residual visibility |
| Tritium (GTLS) | Green / white / other | No | Constant low glow for 10–20 years |
| Basic budget lume | Greenish | Yes | Often fades within 1–2 hours |
Super-LumiNova C3 is the most common high-grade lume. It charges quickly from sunlight or strong artificial light and is extremely bright in the first 30–60 minutes. After that it gradually fades but usually remains usable for several hours.
BGW9 appears more blue-white and is often preferred for its cleaner look in the dark. Many wearers find its residual glow lasts a bit longer than classic C3.
Rolex Chromalight is a proprietary blue emission lume developed for longer residual visibility. It is designed to stay readable longer into the night compared with standard Super-LumiNova grades.
Tritium tubes (gaseous tritium light sources) do not need charging. They glow continuously at a lower level for many years. They never get as bright as a freshly charged Super-LumiNova, but they are always available.
• Amount and quality of lume applied (thicker = brighter and longer)
• How recently and how strongly it was charged
• Age of the lume (older Super-LumiNova slowly loses efficiency)
• Ambient light before going into darkness
• Individual eye adaptation to the dark
Which lume is the brightest? Freshly charged Super-LumiNova C3 and high-grade BGW9 are among the brightest. Chromalight is optimised more for longevity of residual glow than peak intensity.
Does Tritium need to be charged? No. Tritium tubes glow continuously because of the radioactive decay of tritium gas. They require no light charging.
How long does Super-LumiNova stay readable? High-quality C3 or BGW9 is usually easy to read for the first 1–2 hours and remains usable for 4–8 hours depending on application thickness and charge.
Is older lume dangerous? Modern Super-LumiNova is non-radioactive and safe. Vintage radium lume is radioactive and should be handled with care; it is no longer used in new watches.
Why do some watches glow much longer than others? Thicker lume plots, better lume grade, and proprietary formulations (such as Chromalight) all improve residual glow duration.
Can I recharge lume with a phone torch? Yes. A strong LED torch or phone light held close for 20–30 seconds will charge modern photoluminescent lume effectively.