How much light does smoked taillight film take away?
About as much as its rating says it will. The percentage on a smoke film is the share of visible light it lets through, so a 50% film halves what leaves the lens and a 30% film keeps a little under a third. Brookswood Tint sells STEK smoke in those two shades.
STEK lists its own light film shades by transmittance, from DYNOstorm at 50% down to DYNOsmoke at 30%. The arithmetic below uses the rating alone; the lamp’s own lens colour and the viewing angle shift the real figure a little either way.
| Film over the lamp | Light from the lamp that gets out | Light a built-in reflector sends back |
|---|---|---|
| No film | All of it | All of it |
| 50% smoke | About half | About a quarter (0.5 × 0.5) |
| 30% smoke | About 30% | Under a tenth (0.3 × 0.3) |
The source doesn’t matter. An LED brake light and a filament bulb lose the same share, because the film acts on whatever light reaches it.
Why do reflectors lose more than the lamps?
A reflector’s light has to cross the film twice. Headlights from the car behind shine in through the film, bounce off the reflector, and come back out through the film again, so the losses multiply.
That matters because a reflector is what shows a parked car at night with its lamps off. BC’s lamp regulations require at least one red reflector at the rear, “either separate or incorporated into a tail lamp” (s. 4.21). On cars where it’s built into the tail lamp lens, smoke film over the lens covers the reflector too.
How does that compare with what a lamp lens is allowed to lose?
Far more than any lens is allowed to lose to age. The US lamp standard, FMVSS No. 108, puts the plastics used in lamp lenses through three years outside in Florida and Arizona, then fails any material whose luminous transmittance has changed by more than 25%.
Set that beside smoke film. Three years of Florida and Arizona sun is allowed to cost a lens at most a quarter of its light, while a 50% film removes half on the day it goes on, and a 30% film removes about 70%. The standard is written for the lamp as built; film is an extra layer that sits outside that test.
Does film change the difference between the tail lamp and the brake light?
Not the ratio, but it does change the brightness. Where one lamp does both jobs, FMVSS 108 (S7.3.12) requires the stop lamp to be brighter than the tail lamp at every test point by a set multiplier, which is what lets a following driver see the change when you brake.
Film dims both functions by the same share, so that multiplier survives. What doesn’t survive is the lamp’s brightness against its surroundings. At night the background is dark, so a dimmed lamp has less to compete with. In daylight it’s competing with the sun, which is why BC sets its stop lamp test in daylight: s. 4.17(3)(a) calls for “only red light visible from a distance of 100 m to the rear of the vehicle in normal sunlight”. Tail lamps carry a 150 m test, but they matter most after dark.
Can taillight film fail a BC inspection?
Yes, at any shade. Item 1.0(a) in Section 6 of BC’s 2025 Vehicle Inspection Manual fails a lamp whose lens “reduces transmission of light” or “is covered in any manner”, and the regulations require lamps that aren’t “shielded, covered or obscured” by any material (s. 4.04).
On inspection risk: a 50% film is not a safe middle ground. It still reduces transmission, which is the reject wording. The film peels off with heat, so plan to remove it before any designated-facility inspection. Tickets, Notice & Order boxes and fines are set out in are smoked taillights legal in BC.
How do you choose a taillight shade with the dimming in mind?
Pick the lighter shade if the car is a daily driver, and know what’s under the film before you pick at all. The shop recommends its 50% smoke for daily drivers and for housings with amber signals in them, and keeps the 30% for taillights and fog lights on cars going for a blacked-out look.
- Check what shares the lens. If the brake light, signal, reflector and reverse lamp all sit under one lens, every one of them is dimmed by the same film.
- Look at it lit, in daylight. Before committing, ask to see a sample of the shade held over your own lit brake light in the daytime.
- Plan for removal. Inspections, a sale or a change of mind all end the same way: heat, and the film lifts off.
Booking taillight film at Brookswood Tint
If you still want the look, the shop fits STEK smoke in 30% or 50%, heat-formed to each lens, in two to three hours for a pair. The shop publishes a 7-year term on the film against yellowing, cracking and peeling, and explains the brake light and inspection risk before you decide. Shades and housing details are on smoked taillights and the main headlight and taillight film page; the shop says smoked taillights and a chrome delete are booked together more often than not.
Prices are quoted for your model. Ask for a price on the light film request form, or by text at 604 534 6433.