There's no denying the allure of a gadget that can outwit the unblinking eye of the photo-enforcement camera. Whether it's a red light or speed camera or a roving photo radar (speed) van, this technology is used in 22 states and continues to spread.
Red light cameras monitor more than red lights: many also watch for a right turn on red where the vehicle fails to halt. Same for left turns on red, and they're frequently used to generate speeding tickets as well.
Products claiming to defeat cameras fall into three classes: passive, active and radar detectors. Passive products include license plate covers. Made of clear polycarbonate, they have a thin layer of prismatic material positioned over the alphanumeric characters. Viewed at a zero-degree angle—from directly behind—the plate can be read. But as one moves to the side and the angle becomes greater, one or more of the numbers will be obscured. At least that's what the manufacturers promise.
There's also a clear spray called PhotoBlocker that the manufacturer swears will make the plate so reflective, it overexposes the photo. A competing spray, Photo Stopper, is sold by On Track Manufacturing.
Active devices include a solenoid-activated plate-flipper that flattens the plate to hide it. A few adapt electrochoic Smart Glass technology that makes clear glass cloudy by applying an electrical charge. Another blasts the camera with a strobe flash, claiming to blind it.
The plate covers capitalize on the fact that the roadside-mounted camera operates at an angle from the target vehicle's path, called the cosine. Photo radar works the same: the camera is aimed at a shallow angle of 20 to 22 degrees along the road.
Regardless of the type of photo enforcement, to make their case the enforcers must identify the license plate. In some states a photo of the driver is also required. And no plate means no vehicle ID and no ticket.
Some radar detectors can protect against cameras. A GPS-enabled model stores camera locations in a database and can warn when a camera is approached.
To test the plate covers and PhotoBlocker spray we borrowed a $40,000 Multanova photo radar unit. Then we constructed a red light camera system that replicates those of ATS and Redflex, the firms controlling about 90 percent of the domestic automated enforcement market. Learn more about how we tested the plate covers and PhotoBlocker.
We tested the radar detectors against a Redflex red light camera radar in nearby Scottsdale, Arizona. Learn more about how we tested the radar detectors.
The GPS-enabled radar detector was found to be the most reliable defense against red light and speed cameras. Protection against police radar and lasers helps to justify their higher tariff.
Escort invented the GPS-enabled detector and controls key patents. While competitors offer anti-camera models—Uniden, Radenso and Whistler among them—all are missing the features that make Escorts so superior.
We've tested the camera-detecting models from Escort and found some more likable than others. The one we've found the most effective is the Escort Redline 360c.
Low price aside, we found little to recommend any of the license plate covers. Same for the photo sprays. A few of the plate covers seemed promising but none affected our cameras. And some are easy to spot, increasing the risk of being ticketed for an obscured license plate.
The Photo Blocker spray is easily applied and comparatively inexpensive. But while it made some of our license plates very shiny, it had zero effect on the cameras.
Disappointed by the lackluster performance of the passive devices, we concluded that the only reliable camera defense is a radar detector with GPS.
The few models worth having are hardly inexpensive, but we find that it takes more than a can of clear spray paint to neutralize a $50,000 computer-controlled camera system.