Tail Light Output Comparison - Red/Clear/Smoked

[Nexus]

I just did a comparison of 3 different types of lights for my 2019 to see how different they are.

Background:
I swapped out the stock lights for a set of FORM Lighting smoked lenses back in 2022.

Liked their stock look and the smoked lenses, but had some concerns about their lack of light output compared to stock , specifically on a sunny day and the brake brightness.

I did email them about this but the response was "The difference in overall brightness is pretty marginal, and will still be plenty bright for both usage during the day, and at night. Unfortunately, we do not have any exact lumen specifications compared to stock, however they should be pretty similar overall".

This year I decided to upgrade to a set of Morimoto XB clear lenses with the amber turn signal.
During install I decided to get a light meter and compare the 3 to see the difference.
Pulled out the stockers and away we go.

The Setup (in no way am I saying this is a proper setup or test, just an interesting comparison under the same circumstances)
-Dark Garage and no other lights on.
-The same light location each time (left rear light only, right unplugged)
-License plate lights covered.
-Light meter placed 2.5ft behind the left tail light. (limitation with the length of my garage)
-Meter registered 0 lux with both lights unplugged and the car being unlocked to verify no other light source hitting the meter.
-All tested same day, same condition 10 minutes apart.

Results in Lux:

Stock Red:
Light On - 42
Brake/Signal Light - 548

FORM Smoked:
Light On - 7
Brake/Signal Light - 46

Morimoto Clear:
Light On - 14
Brake Light - 86
Signal Light - 117(Amber)

Shows you just how bright the stock eye searing red tails are, and don't believe the 'brighter than stock' claims.

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[9secondko]

Nice work. Good to see hard numbers. Thanks for measuring.

I love the smoke head/taillights on certain paint colors.

but they do clearly reduce brightness, which is a safety feature.

Would be nice for a manufacturer to offer brighter lights that make up the difference behind the smoked housings.

 

[tomservo92]

This is interesting as I'm considering the FORM smoked tails. I was curious if there is a minimum DOT brightness requirement from the government but there isn't one that I could find. That actually suprised me as they want to regulate everything else.

 

[Nexus]

I did find some tables on the subject after some digging:
FMVSS 108 (US)
TSD 108 (Canada)

They have tables on the photometry requirements in candela (cd).
The fun part is each table has test points at degrees from the light source and its required min/max values.

cd to LUX

You'd figure that as a min it would be around what the federal requirements are, but I'd want to make them as close to stock output as possible.
I don't doubt it comes down to cost and some other factors.

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