这个东东不错
- 主题发起人 胖蹄阿克
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新手上路
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- 2002-01-24
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You may believe that red light cameras and photo radar are part of the Trilateral Commission's conspiracy to turn the proletariat into tools of the military-industrial-banking complex. Or, you may think that drivers who are caught by red light cameras deserve what they get. But everyone's reaction is the same when the Postman knocks with a hundred-buck ticket.
They're pissed!
Red light cameras are big business. It's not uncommon for the systems to be installed and managed by large corporations, who by the way process the tickets and send them to the offender while taking a slice of the proceeds and passing the rest back to the local city or county government.
Matt Labash's excellent article "Inside the District's Red Lights" from the Weekly Standard (April 2002) details the use of red light cameras in Washington, D.C. In the first couple of years of use, red light cameras in Washington, D.C. generated over $15.5 million in revenue for the District. No one seems bothered that "A private company is given police power to ticket citizens, has a monetary interest in generating as many tickets as possible, and, despite its low success rate, is often allowed to do so with minimal or no police supervision."
Governments like to find alternate sources of revenue and they like to spend money, so the allure of free cash in the form of red light camera revenue is irresistible, and the devices are becoming very popular. And they see no problem with a private company being given police powers to ticket citizens, has a monetary interest in generating as many tickets as possible, and, despite its low success rate, is often allowed to do so with minimal or no police supervision
Photo Blocker and LensHave they decreased accidents? Who cares when all that money is flowing into the coffers!
A rather convincing study about the efficacy of red light cameras was conducted in 1995 by David Andreassen for the Australian Road Research Board. "A long term study of Red Light Cameras and Accidents", (ARR 261) concluded that accident rates at intersections can increase when red light cameras are used. The study covered a 10-year period and concluded that the use of cameras for enforcement "did not provide any reduction in accidents, rather there have been increases in rear end and cross-street accidents".
Some studies indicate that increasing the length of the yellow light actually decreases the accident rate at intersections (See "Red Lights, Loot and the Law" by Csaba Csere, Car and Driver, September 2001). But longer yellows don't raise any revenue; in fact, it's been postulated that the length of time that the traffic lights show yellow has actually been decreased in some cities, and the conspiracy theorists say this is to help increase the revenue generated by the red light cameras and to hell with public safety.
Which brings us to Photo Blocker. This product is a clear coating that is sprayed on a clean license plate. It's claimed to "reflect photo radar flash" and that it will "make your license plate invisible to cameras". It's probably illegal to mess with your license plate, but it would probably be almost impossible to tell that the plate was treated with the clear Photo Blocker spray. The idea is that the spray will cause the license plate to reflect light back to the camera, over-exposing the photo and making the plate impossible to read by the photo camera.
Phantom Plate, the company that markets Photo Blocker, also sells a product called the "PhotoShield". This device is made from various shapes of translucent plastic that have what appears to be some sort of magnifying qualities. A PhotoShield is supposed to be placed over the license plate to help obscure the characters on the plate by distorting the way the plate's letters or numbers appear in the camera.
Do these products work as advertised? We did a very unscientific study to see if we could tell. Since photo radar cameras are set at different heights and distances from traffic, and can either be on the right or left sides of the road (depending upon which country you're in), we standardized on our own distance and height just for comparison purposes.
We don't know what exposure values are used by the various roadside radar cameras, and apparently some of the cameras don't use a flash. Since the Photo Blocker spray is supposed to work by reflecting back the camera's flash, if no flash is used, we would assume that the Photo Blocker would be ineffective. Keep that in mind next time your riding in red light camera territory.
The printed and online marketing literature for the Photo Blocker and PhotoShield products show various before and after photos. Some of the photos appear to be taken from directly behind the license plate. We don't think there are many red light cameras that are configured to take their photos from directly behind a license plate, so we're not sure if before/after photographs taken from directly behind the license plate is a valid method to demonstrate the effectiveness of the product.
Most of the radar cameras we've seen in Montgomery County, Maryland and in downtown Washington, D.C. are set high up on traffic poles off to one side of an intersection. Something to consider is that the angle of the flash will probably bounce the light off the plate in an opposite but equal angle. Remember high school geometry? It took me 3 semesters to pass it, but I do remember something about the angle of incidence equals the angle of reflection. So it would seem logical that if the camera and flash are above and to the side of the license plate that the light from the flash will reflect off at an equal but opposite angle. If this is true, then even if the license numbers were painted on a mirror, they'd still be visible to the camera, no? You scientific brains can tell me if we're wrong or not.
We set the camera 10 feet to the right of a parked motorcycle, at a distance of 25 feet at an angle of 22.5 degrees from the rear of the bike. The camera's lens was 6 feet high. We used a Nikon D70 digital camera with a Nikon 80-200 f2.8 AF-D ED lens set at its 200mm focal length, and a Nikon Speedlight 800 flash (Nikon's most powerful), set to use fill-flash. The flash fired on each photo. The motorcycle shown in these photos faces north; it was mid-morning, and the sun was up in the east on a sunny and clear day with low humidity. We tried various exposure settings and compared the photos, but there didn't seem to be any noticeable difference in the quality of the photo or in the visibility of the license plate, so we settled on f8 at 1/125 second exposure, which is a "classic" sunny day camera setting.
We used two expired Maryland license plates to compare the application of the Photo Blocker spray. Both plates were cleaned with soap and water and dried prior to the study, and they were in almost new condition. One plate was sprayed with the Photo Blocker following the directions, which indicate that several coats should be applied until a gloss coat appears on the plate. We used the two plates so that we could leave the motorcycle and camera in exactly the same position between photos and so that we'd have a treated and untreated plate for more study if warranted.
The photos below show the results. These photos are un-retouched with the exception of a 10% sharpening in Microsoft PhotoDraw. Photo 1 is the untreated license plate. Photo 2 shows the license plate treated with Photo Blocker. Photo 3 shows the untreated license plate with the PhotoShield lens attached. Photo 4 shows the license plate treated with Photo Blocker and the PhotoShield lens attached. The PhotoShield lens had a slight bow on the right side, causing the slight distortion of the numbers on the plate in photos 3 and 4. We assume that if this distortion could be amplified over the plate that it might cause the numbers to be unreadable.
Photo 1: Not treated with Photo Blocker; no PhotoShield lens.
Photo 2: Treated with Photo Blocker coating; no PhotoShield lens.
Photo 3: Not treated with Photo Blocker; PhotoShield installed.
Photo 4: Treated with Photo Blocker coating; PhotoShield installed.
We didn't have the capability of mounting the camera at more than 6 feet high or at various distances from the motorcycle, so results may vary. We have no comment on the efficacy of these products and will leave it up to the reader to interpret the results. If you have any comments on this product or how this study was conducted, please send them to me at
http://www.webbikeworld.com/r2/photo-blocker/
They're pissed!
Red light cameras are big business. It's not uncommon for the systems to be installed and managed by large corporations, who by the way process the tickets and send them to the offender while taking a slice of the proceeds and passing the rest back to the local city or county government.
Matt Labash's excellent article "Inside the District's Red Lights" from the Weekly Standard (April 2002) details the use of red light cameras in Washington, D.C. In the first couple of years of use, red light cameras in Washington, D.C. generated over $15.5 million in revenue for the District. No one seems bothered that "A private company is given police power to ticket citizens, has a monetary interest in generating as many tickets as possible, and, despite its low success rate, is often allowed to do so with minimal or no police supervision."
Governments like to find alternate sources of revenue and they like to spend money, so the allure of free cash in the form of red light camera revenue is irresistible, and the devices are becoming very popular. And they see no problem with a private company being given police powers to ticket citizens, has a monetary interest in generating as many tickets as possible, and, despite its low success rate, is often allowed to do so with minimal or no police supervision
Photo Blocker and LensHave they decreased accidents? Who cares when all that money is flowing into the coffers!
A rather convincing study about the efficacy of red light cameras was conducted in 1995 by David Andreassen for the Australian Road Research Board. "A long term study of Red Light Cameras and Accidents", (ARR 261) concluded that accident rates at intersections can increase when red light cameras are used. The study covered a 10-year period and concluded that the use of cameras for enforcement "did not provide any reduction in accidents, rather there have been increases in rear end and cross-street accidents".
Some studies indicate that increasing the length of the yellow light actually decreases the accident rate at intersections (See "Red Lights, Loot and the Law" by Csaba Csere, Car and Driver, September 2001). But longer yellows don't raise any revenue; in fact, it's been postulated that the length of time that the traffic lights show yellow has actually been decreased in some cities, and the conspiracy theorists say this is to help increase the revenue generated by the red light cameras and to hell with public safety.
Which brings us to Photo Blocker. This product is a clear coating that is sprayed on a clean license plate. It's claimed to "reflect photo radar flash" and that it will "make your license plate invisible to cameras". It's probably illegal to mess with your license plate, but it would probably be almost impossible to tell that the plate was treated with the clear Photo Blocker spray. The idea is that the spray will cause the license plate to reflect light back to the camera, over-exposing the photo and making the plate impossible to read by the photo camera.
Phantom Plate, the company that markets Photo Blocker, also sells a product called the "PhotoShield". This device is made from various shapes of translucent plastic that have what appears to be some sort of magnifying qualities. A PhotoShield is supposed to be placed over the license plate to help obscure the characters on the plate by distorting the way the plate's letters or numbers appear in the camera.
Do these products work as advertised? We did a very unscientific study to see if we could tell. Since photo radar cameras are set at different heights and distances from traffic, and can either be on the right or left sides of the road (depending upon which country you're in), we standardized on our own distance and height just for comparison purposes.
We don't know what exposure values are used by the various roadside radar cameras, and apparently some of the cameras don't use a flash. Since the Photo Blocker spray is supposed to work by reflecting back the camera's flash, if no flash is used, we would assume that the Photo Blocker would be ineffective. Keep that in mind next time your riding in red light camera territory.
The printed and online marketing literature for the Photo Blocker and PhotoShield products show various before and after photos. Some of the photos appear to be taken from directly behind the license plate. We don't think there are many red light cameras that are configured to take their photos from directly behind a license plate, so we're not sure if before/after photographs taken from directly behind the license plate is a valid method to demonstrate the effectiveness of the product.
Most of the radar cameras we've seen in Montgomery County, Maryland and in downtown Washington, D.C. are set high up on traffic poles off to one side of an intersection. Something to consider is that the angle of the flash will probably bounce the light off the plate in an opposite but equal angle. Remember high school geometry? It took me 3 semesters to pass it, but I do remember something about the angle of incidence equals the angle of reflection. So it would seem logical that if the camera and flash are above and to the side of the license plate that the light from the flash will reflect off at an equal but opposite angle. If this is true, then even if the license numbers were painted on a mirror, they'd still be visible to the camera, no? You scientific brains can tell me if we're wrong or not.
We set the camera 10 feet to the right of a parked motorcycle, at a distance of 25 feet at an angle of 22.5 degrees from the rear of the bike. The camera's lens was 6 feet high. We used a Nikon D70 digital camera with a Nikon 80-200 f2.8 AF-D ED lens set at its 200mm focal length, and a Nikon Speedlight 800 flash (Nikon's most powerful), set to use fill-flash. The flash fired on each photo. The motorcycle shown in these photos faces north; it was mid-morning, and the sun was up in the east on a sunny and clear day with low humidity. We tried various exposure settings and compared the photos, but there didn't seem to be any noticeable difference in the quality of the photo or in the visibility of the license plate, so we settled on f8 at 1/125 second exposure, which is a "classic" sunny day camera setting.
We used two expired Maryland license plates to compare the application of the Photo Blocker spray. Both plates were cleaned with soap and water and dried prior to the study, and they were in almost new condition. One plate was sprayed with the Photo Blocker following the directions, which indicate that several coats should be applied until a gloss coat appears on the plate. We used the two plates so that we could leave the motorcycle and camera in exactly the same position between photos and so that we'd have a treated and untreated plate for more study if warranted.
The photos below show the results. These photos are un-retouched with the exception of a 10% sharpening in Microsoft PhotoDraw. Photo 1 is the untreated license plate. Photo 2 shows the license plate treated with Photo Blocker. Photo 3 shows the untreated license plate with the PhotoShield lens attached. Photo 4 shows the license plate treated with Photo Blocker and the PhotoShield lens attached. The PhotoShield lens had a slight bow on the right side, causing the slight distortion of the numbers on the plate in photos 3 and 4. We assume that if this distortion could be amplified over the plate that it might cause the numbers to be unreadable.
Photo 1: Not treated with Photo Blocker; no PhotoShield lens.
Photo 2: Treated with Photo Blocker coating; no PhotoShield lens.
Photo 3: Not treated with Photo Blocker; PhotoShield installed.
Photo 4: Treated with Photo Blocker coating; PhotoShield installed.
We didn't have the capability of mounting the camera at more than 6 feet high or at various distances from the motorcycle, so results may vary. We have no comment on the efficacy of these products and will leave it up to the reader to interpret the results. If you have any comments on this product or how this study was conducted, please send them to me at
http://www.webbikeworld.com/r2/photo-blocker/
