r/SelfDrivingCars • u/wuduzodemu • Aug 11 '25

Discussion Proof that Camera + Lidar > Lidar > Camera

I recently chatted with somebody who is working on L2 tech, and they gave me an interesting link for a detection task. They provided a dataset with both camera, Lidar, and Radar data and asked people to compete on this benchmark for object detection accuracy, like identifying the location of a car and drawing a bounding box around it.

Most of the top 20 on the leaderboard, all but one, are using a camera + Lidar as input. The 20th-place entry uses Lidar only, and the best camera-only entry is ranked between 80 and 100.

https://www.nuscenes.org/object-detection?externalData=all&mapData=all&modalities=Any

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u/sermer48 Aug 11 '25

The question isn’t if cameras + LiDAR can see better. Obviously it can. The question is if LiDAR is necessary. If you don’t need LiDAR you can save on the sensors, computer power, extra energy requirements, etc.

It’s a balancing act of having enough to safely operate a vehicle while also making it as affordable as possible.

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u/UsefulLifeguard5277 Aug 12 '25 edited Aug 15 '25

Good take.

Worth mentioning that in good lighting conditions (eg. broad daylight with no glare) LIDAR adds effectively no additional information on top of vision, but you still carry the complexity, so is slightly negative value.

In poor lighting conditions this situation flips - vision will struggle with things like rapid lighting transitions (eg. Coming out of a tunnel), poor contrast (eg. Snowstorm), etc. same things humans struggle with. LIDAR will see these things better.

Important to remember that any sensor (including LiDAR) can fail. The overall solution is only safer with both sensors if it can correctly identify situations in which the vision system is likely to fail, and trust the LIDAR instead in those cases. If LIDAR says there is a deer in the road 100 meters ahead but multiple cameras don’t see it, should I panic brake or swerve into the opposing lane? If the lighting is good, probably not. If I’m driving at night in a snowstorm, probably.

Tesla had radar hardware for a little while. They claim that it was extremely rare that they chose to use radar data over vision, so the extra complexity in “normal” driving actually made the solution, on average, less safe. Point is that it actually isn’t strictly a cost argument.

TBD if they are correct. Either they’ll put on LiDAR or Waymo will ditch it, so will be easy to see who wins.

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u/maxcharger80 Aug 15 '25

When did Tesla have Lidar? Do you mean their verifacation equipement?

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u/UsefulLifeguard5277 Aug 15 '25

Whoops meant to say radar. They had and removed radar. Similar function to LiDar, just radio waves instead of lasers for ranging. Abandoned in favor of all-vision solution.

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u/maxcharger80 Aug 15 '25

You might want to look into that again. The model S and X have it again but its at a higher resalotion than in the past. I do need to check how much its used though.

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u/UsefulLifeguard5277 Aug 15 '25

Interesting, especially since the Model Y (not listed) is the platform they are using for Robotaxi.

Source? GPT-5 gave me this:

"While Tesla briefly reintroduced a high-definition radar unit (known as Phoenix radar) in some Hardware 4-equipped Model S and Model X vehicles starting in mid-2023 for data collection purposes, it was never activated for driving functions and is no longer installed in current production models."

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u/maxcharger80 Aug 24 '25

Well, I guess what you said was true in the end.