When it comes to curing gels, UV lamps are considered the old-school option—they cure gels slower compared to the more modern LED lamps, which are much faster. But there’s a common misconception: LED lamps do still emit UV light, even though they use a different kind of bulb.

So, what’s the difference? The main one is the bulb. UV lamps use CFL bulbs (Compact Fluorescent Lamps), while LED lamps use LED bulbs (Light Emitting Diodes). The LED name refers to the type of bulb, not the UV light it emits.

🧪 Measuring UV Light – Wavelengths and Intensity

When it comes to light, there are two key things we measure:

• Wavelength (measured in nanometres, or nm)
• Intensity (measured in milliwatts per square centimetre, or mW/cm²)

You can think of UV light as having different flavours. These flavours are the wavelengths, and the strength of each flavour is the intensity.

What is Wavelength?

Wavelength refers to the “flavour” of the light. In the Electromagnetic Spectrum, each wavelength (or flavour) is represented by a number. The numbers tell you where that wavelength falls in the spectrum.

Each number (shown at the bottom of the image) is a flavour.

What is Intensity?

Intensity is how strong the flavour is. It tells you how much UV light is being emitted. Just like making a chocolate ice cream, if you add too much (or too little) cocoa, you get a different flavour. The intensity of UV light can be influenced by a few factors:

Key Factors that Affect UV Intensity

1. Wattage of the Bulb
   • Think of the difference between a 25-watt bulb and a 75-watt bulb. A 75-watt bulb will produce brighter light than a 25-watt bulb, and the same principle applies to your gel lamp. A 9-watt bulb will be stronger than a 4-watt bulb, resulting in faster curing.
2. Number of Bulbs
   • The more bulbs you have in the lamp, the greater the intensity. Just like if you have 4 light bulbs in a room versus 12, the room will be brighter with more bulbs. The same happens in your gel lamp: more bulbs = more UV intensity.
3. Distance from the Nails
   • Distance plays a big role in how strong the UV light is. Imagine someone shines a torch at you from far away (several metres)—you’ll barely see the light. But if they shine it from 10 cm away, you’ll see every pore and freckle on your skin.
   • The closer the bulbs are to the nails, the faster the gel will cure. If the bulbs are too far away, the gel may not cure properly at all, just like how you may not see the details on your skin if the light is too far away.

Narrow Wavelengths

LED lights use a wavelength (back to flavours) that’s much narrower than that of CFLs. This narrower wavelength emits just the right amount of UV-A light needed to cure LED gels—which is why LED cures faster.

Think of it like this:

Imagine you need 2L of strawberry ice cream, but the shop only sells tubs of Neapolitan (the kind with chocolate, strawberry, and vanilla stripes). You’d need to buy multiple tubs just to get enough strawberry flavour.

But if they sold tubs of just strawberry, you’d only need one tub and you’d be done much more efficiently.

LED lamps work the same way—they give you only the UV light that’s needed, without any excess.

In technical terms:

Most gels need a wavelength between 340-380 nm to cure, though it can vary by brand. For example, one brand may cure best at 350 nm, while another may prefer 375 nm.

• A CFL/UV lamp designed for a gel rated for 350 nm will emit a broad range of light, ranging around 80 nanometres, roughly from 320 to 400 nm—think of it as the Neapolitan ice cream.
• An LED lamp designed for the same gel will emit light that’s more precise, typically in the range of 345 to 355 nm—this is your plain strawberry.

This precision makes LED lamps more efficient, giving you the exact wavelength needed without any unnecessary extras.