Here's a move we see all the time: someone doesn't like how their light throws, so they go shopping for a new flashlight. Nine times out of ten that's the expensive fix to the wrong problem. The part that decides what your beam actually looks like is a stamped piece of aluminum or a molded chunk of plastic sitting behind the lens, and it usually costs two bucks and swaps out in about ninety seconds.
If you've never opened the head of a light before, this is the single highest-payoff thing you can learn. Here's what each optic does, and how to pick the one that matches how you actually use the light.
The optic controls shape, not brightness
First, get the vocabulary straight, because product listings blur it constantly.
Lumens is total light output. That's the emitter and driver's job. Beam profile is where that light goes — and that's the reflector or lens. Swapping optics doesn't make a light meaningfully brighter or dimmer. It takes the same pile of photons and redistributes them.
Three parts of a beam matter:
- Hotspot — the bright center circle.
- Corona — the transition ring between hotspot and spill.
- Spill — the dimmer flood around the edges that lights up everything near you.
Every optic below is just a different tradeoff between those three.
Smooth reflector (SMO): distance
A mirror-polished cone. It collects light off the emitter and collimates it tightly, which gives you the smallest, most intense hotspot and the most reach out of a given light.
The catch is honesty — a smooth reflector is a mirror, so it faithfully reproduces whatever the emitter looks like. You'll see the LED's die pattern projected in the hotspot, sometimes a visible square or a dark spot in the middle, plus ringy artifacts in the corona. On a thrower pointed at a treeline 150 yards out, nobody notices or cares. On a white wall at arm's length, it looks messy.
Pick SMO if: you're identifying things at distance — property lines, a field, the far end of a warehouse, spotting from a stand.
Orange peel (OP): the safe default
Same cone, but the surface is dimpled like the skin of an orange. Those dimples scatter the reflected light just slightly, which blends the emitter artifacts into a clean, even hotspot with a soft transition into the spill.
You trade a bit of maximum reach for a much nicer-looking beam. Honestly, for most people, that's not a trade at all — it's an upgrade, because "a bit less throw" is invisible in real use while "no ugly rings" is visible every single time you turn the light on.
If you're not sure which one you want, buy orange peel. Our Convoy S2+ reflectors come in both smooth and OP for $1.99, so you can genuinely just get one of each and decide with your own eyes instead of arguing about it online.
Pick OP if: you want one beam that does everything acceptably — walking, working, searching a yard, general EDC.
TIR optic: the clean flood
A TIR (total internal reflection) lens is a solid optic that sits over the emitter and bends light through the material itself instead of bouncing it off a cone. Because there's no reflector cavity, there's no ring structure and no artifacts — you get a smooth, wide, even beam with a soft-edged hotspot and no hard cutoff.
TIRs are also efficient at capturing light that would otherwise escape sideways past a shallow reflector, and they're physically shorter, which is why so many compact modern lights use them.
What you give up is distance. A TIR spreads light out; that's the whole point. Don't buy one expecting to reach across a field. A Convoy S2+ TIR lens runs $0.99, which makes "try it and see" a very cheap experiment.
Pick TIR if: you work close — under a hood, in a crawlspace, at a bench, around a campsite, anywhere a hot bright dot in the middle of your vision is a nuisance rather than a feature.
Diffusers: flood on demand
The optic swap is permanent until you open the light again. A diffuser is the reversible version.
D-C-Fix diffuser film is the flashlight community's worst-kept secret — three dollars of adhesive-backed frosted film that you cut to size and stick over your lens. It turns a tight thrower into a soft lantern-grade flood instantly. Cut a few discs from one sheet and keep spares.
There's also the red slip-on diffuser, which does double duty as a traffic wand and as a way to preserve dark-adapted vision when you don't want to blast white light around camp.
The lens itself is worth a dollar of attention
Separate from the optic, the flat glass window on the front costs you a couple percent of your output through reflection. An AR-coated lens cuts that loss. It's not a beam-shape change and you won't see it side by side — but if your existing lens is scratched, that's the replacement to buy, and the coating is basically free at that point.
Actually doing the swap
On a Convoy S2+ or most similar hosts, this is a five-minute job with no soldering:
- Unscrew the bezel from the head. If it's stuck, round-nose pliers exist for exactly this and will save you from gouging the knurling with channel locks.
- Lift out the lens, the lens gasket, and the reflector. Note the order they came out in.
- Drop the new optic in. Don't touch the inside of a reflector with bare fingers — fingerprints on that surface are permanent and you will see them in the beam.
- Reassemble. Replace the o-rings and gaskets if they look flattened or dry — they're the entire water seal, and they cost about a dollar for a ten pack in our Convoy parts collection.
One thing to watch: reflector height matters. A reflector that doesn't seat flush against the emitter shelf will give you a dark ring or a defocused hotspot. If your beam looks wrong after a swap, that's almost always the cause — not a bad part.
Bottom line
Beam shape is the most noticeable characteristic of a flashlight and the cheapest one to change. Before you spend a hundred dollars solving a beam complaint, spend five: get an OP reflector and a TIR lens, run them both for a week each, and find out what you actually prefer. Most people discover they've been carrying the wrong beam for years and never knew there was a two-dollar fix.