Flashlight Optics Explained: TIR Lens vs. Reflector and Converging Lenses

If you’ve ever owned more than one flashlight, you’ve noticed they don’t all produce the same beam of light. One might create a soft, wide circle. Another might project an intensely bright “hotspot” with a dim “spill” around it.

And if you’ve used certain high-power spotlights, like the one on the Olight Marauder 2, you may have seen something really strange: the beam it projects is a perfect square.

Why? It’s not a defect. It’s by design. The shape, quality, and intensity of a beam are all controlled by the optics—the hardware that sits in front of the LED. Let’s break down the three main types.

1. The Classic: The Reflector

For decades, the “reflector” has been the standard. This is the simple, bowl-shaped, mirror-finish component you see surrounding the LED. Its job is simple: catch all the light firing sideways and backwards from the LED and reflect it forward.

Reflectors come in two main flavors: * Smooth (SMO): A polished, mirror-like surface. It’s excellent for maximizing “throw” (candela), but it can produce artifacts or “rings” in the beam. * Orange Peel (OP): A textured, bumpy surface. This texture smooths out the beam, creating a softer hotspot and a more pleasant, artifact-free light, slightly sacrificing maximum throw.

2. The Modern Floodlight: The TIR Optic

Reflectors are great, but they can be bulky and aren’t always the most efficient. This led engineers to develop a more compact and advanced solution, especially for floodlights: the TIR (Total Internal Reflection) Optic.

A TIR optic is a piece of molded plastic or glass that looks more like a high-tech showerhead than a simple bowl. It does two jobs at once:
1. Refracts: It acts like a lens, bending light that passes through it.
2. Reflects: It uses the principle of “total internal reflection” (like a fiber optic cable) to bounce light off its internal surfaces.

This total control allows engineers to design exactly the beam shape they want. TIRs are often used to create a wide, smooth, “wall of light.” When a flashlight like the Marauder 2 uses 12 LEDs for its floodlight, it’s using an array of TIR optics to blend them all into one massive, even beam with no ugly hotspots.

3. The Ultimate Thrower: The Converging (Collimating) Lens

But what if you don’t want a wide, soft beam? What if you want to concentrate all your power into a single, intense point 800 meters away? For that, you need a different tool: the converging lens.

A converging lens (or “collimating lens”) sits on top of the LED and acts like a powerful magnifying glass. It gathers all the scattered light from the LED and forces it into a perfectly straight, parallel beam (a “collimated” beam).

This is the key to maximum candela and “throw.” It’s how a dedicated spotlight creates that pencil-thin beam.

But this method has a fascinating side effect. Because the lens is essentially projecting an image of the LED itself, the “hotspot” is no longer a round circle. Instead, the beam takes on the shape of the LED emitter chip. Most modern, high-power LEDs (like the one used in the Olight’s spotlight) are square.

So, if your flashlight beam is a square, it’s a clear sign you’re holding a high-performance “thrower” that uses a powerful converging lens.

Conclusion: The Right Tool for the Job

There is no single “best” optic. The choice of hardware defines the light’s purpose: * Reflectors are the classic, balanced all-rounders. * TIR Optics are the modern solution for clean, efficient, wide-angle floodlights. * Converging Lenses are the specialists for creating maximum-distance spotlights.

The most advanced lights often use a combination of these technologies, giving you both a wide “TIR-style” floodlight and a “lens-style” square-beam spotlight in one package.