PhotoBlocker is a clear spray that its maker claims will make the plate so reflective, a red light camera will be blinded by its own flash. Suggested retail price is $49.95.
Following Photoblocker's directions, we applied four coats to each of our test license plates and allowed them to dry for an hour between coats.
The plates were chosen for their color and reflectivity. One was a highly retroreflective California plate. We also included an older, dark blue Michigan plate and one from Colorado (dark green background, white alphanumeric characters).
After running the California plate past our red light camera and photo radar, in photos the plate looked slightly brighter than its untreated sibling. But the numbers remained clearly legible. PhotoBlocker-coated Michigan and Colorado plates were indistinguishable from uncoated versions and our cameras remained equally unfazed.
The ingredients on the can of PhotoBlocker looked remarkably similar to those on the can of Ace Hardware clear gloss spray paint ($3.99) we retrieved from the garage. On a hunch, we coated another set of plates with the Ace Hardware stuff and repeated the test—with identical results.
The laws of physics likely defeated PhotoBlocker and our Ace Hardware clear spray paint. The substantial distance and sharp angles between the plate, strobe flash and camera would dissipate any increased light long before it could reach the camera lens. And the camera's polarizing filter can brush aside any extra glare.
Regardless, most red light cameras record digital video of violations. Technicians can easily fast-forward through an interfering flash of light with a mouse-click.
Skeptics may point to videos where the spray seems to be working. After studying a few of the clips, with some experimentation we discovered how they made it appear the spray works.
Choosing a light-colored, highly reflective license plate like California's is very helpful. So is positioning the camera at plate level and point-blank range. By bumping up camera flash exposure EV value to +5, eventually we managed to overexpose an image. But we found that impossible to do from 80-plus feet away, typical range for a red light camera.
Even on the dark blue—and camera-unfriendly—old Michigan plate, the numbers could easily be read by the camera. Our conclusion is that while we'd like to believe that a can of clear lacquer spray paint will stymie a photo camera, the reality is a bit different.
See how this product compared with others in the recent Red Light Camera Countermeasures test.