Red Light Answer

[Mike Gray]

Originally Posted by Bernie Cunningham

As far as I know, that type of sensor is no longer used, as in where light reflections or flashes would cause them to 'switch'.

These days the units are a sender and receiver across the track and must communicate with each other to 'switch'

So when the funny cars take out the 1/8 mile and finish line foam blocks there is not just a reflector in the blocks but a receiver or sender?
Did it use to be just a reflector? maybe that's where the idea of wheel reflection got started.
Camera flashes for an instant are very bright, I hate the annoying flashes from overhead strobes at NBA games that are triggered by the photographers camera.
If I watch a replay in slow motion it will white out my tv screen.