Originally Posted by techwhiz
It is possible for it to work.
The camera shutter has to be synced with the flash.
A sensor can detect and flash a strobe much faster than the shutter can close.
A fast shutter can be 1/1000 of a second but it also means that your sensor must be sensitive enough with an aperture large enough so you don't underexpose. The cells force an overexposure and the image gets blown.
Now, here in Ca. some jurisdictions play with the timing so as to force a red light hit even if you enter on a "stale green"/early yellow.
There is a "point of no return" where even if you see the light turn yellow, it would be unsafe to stop and either cause the person behind to stop abruptly or run into you OR get you stuck in the middle of the intersection. Some areas set the timing up so short to cause false positives on the red light cameras for revenue generation.
$350 is expensive because what it does is simply the function of a "salve" flash.
You could do a similar function with a camera slave flash if the photo detector was placed in the right location. A slave flash can be had for $35 or so. One tenth the price of this unit.
It's not complicated, either a person ran a red light, or they didn't. Yes, no. Black, white.
There are 3 pics on a summons--one, showing that the vehicle is behind the stop light, on RED. two, showing the vehicle proceeding through the intersection, on RED. three, a close-up of the vehicle's plate.
Why do people make it so complicated, as if running a red light is subject to interpretation?
If you cross the light on green, or yellow, you do not trigger the camera. If someone else triggers the camera and you're in the intersection, guess what? There isn't pic # 1 showing that the light was red, and you were behind the line.
In DC/MD this is a non-issue. You could conceivably spend $1200 in fines just going across town, if you didn't follow the law.