Retroreflective Paint and ALPR

Discussion in 'Passive Countermeasures' started by Black16, May 8, 2018.

  1. Black16

    Black16 Learning to Drive General User

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    Hello all,

    I live in Pennsylvania where only state police can use radar and laser so I consider us residents pretty fortunate (though I heard that might change soon). I have a V1 and I drive fairly responsibly so I'm not too focused on that aspect of this forum. I am not a tin foil hat kind of person and I am not looking to skirt red light cameras and toll booths. I do like to limit the amount of overreach that has been allowed with these systems. PA allows both private industry and parking enforcement to use ALPRs not to mention the state's highways are littered with them.

    This is more just a small experiment that I want to attempt and in my solid 5 minutes of Googling could not find whether this has been done and if it has had success.

    What I have been researching are countermeasures to plate readers and what I've found, hopefully to be correct is,
    -Plates are retroreflective (most likely 3m sheeting) everywhere except the numbers.
    -I think retroreflective surfaces will reflect both a traditional camera flash and IR but will do nothing to prevent reading when there is enough visible light.
    -People have successfully used retroreflective house numbers on their plate to create a solid retroreflective surface (unfortunately PA plates have dark blue letters/numbers.)

    My plan
    -Order the plate attached below due to its noisy background and white lettering
    -Use retroreflective acrylic paint which employs "micro glass beads" similar to roadway paint
    -Apply the paint to some or all of the white area, at least enough to break up their appearance to a machine.
    [​IMG]


    Thoughts and feedback are welcome. Did a quick search in passive countermeasures but couldn't really find if this had been attempted.
     
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  2. RaptorALP

    RaptorALP Premium Member General User Premium Member

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    Aren't there times when you DO want your plate to be parseable by Camera? e.g. Going under certain toll roads/bridges they will not only scan your <insert name of thing that you legitimately pay for the toll road with> but also scan your plate. Maybe this doesn't happen in Penn.
     
  3. Eloi

    Eloi Premium Member Advanced User Premium Member

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    What you want is equiluminance between the background/ letters-numerals.You need to paint/reflectorise whichever is not.


    I tested it with semi-success , very hard to transform a dark color into light color ...merely a "miracle".

    Cops use photoshop in hard to read plates.

    Even harder when they use visible/infrared.

    Equiluminance + active supplement of light might help.

    Good research , keep us updated !
     
  4. Black16

    Black16 Learning to Drive General User

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    PA does use a toll by plate system, however, I have EZ pass so it should not be using my plate to bill me.

    I cannot find a definitive answer on if the entire plate is retroreflective or just the background. I will have to do some testing to find out. I think I am almost trying to acheive the opposite of veil, instead of dulling the plate trying to make it entirely reflective.

    I ordered some "lightning" brand retroreflective paint, easily found on amazon.
     
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  5. Black16

    Black16 Learning to Drive General User

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    Found some time to test this out a bit. Did it live up to my expectation? Yes. Will it work? I don’t know for sure yet. I applied Lightning brand retroreflective paint to the lightest area of the plate, the clouds, which also happens to be between several letters and numbers. This lighter area, made even slightly lighter in daylight using the paint makes it difficult to read the letters and numbers due to lack of high contrast. At night, the paint combined with the retroreflective numbers and letters washes that entire area out to appear as one giant white blob when light or IR hits it.

    I also lightly sanded down the retroreflectivity of the existing letters and numbers to achieve what Eloi called, equiluminance. Sorry the photos aren’t the greatest but I didn’t want to include my entire plate.

    The first two pictures are the new unaltered plate using a camera flash for the photo(flat background with retroreflective numbers and letters, opposite of normal PA plates)

    The second two pictures are after applying the paint to the area with clouds in the background using camera flash.

    The third set of two pictures are the plate after applying the paint and viewed through a Ring video doorbell in the night vision/IR mode.


    Unaltered with flash
    03824858-67C9-480D-9543-E5DB975D4FBF.jpeg D135D40A-6F35-4960-BB90-4CEC81348F29.jpeg

    Altered with flash
    16F01AC8-D4B4-4CF9-936A-C8575B5F027A.jpeg 2B7F293C-F94B-4DDB-A945-BF741E52226D.jpeg

    Altered under IR
    41E73FCA-DFC3-43A5-A96B-30A6EED40631.jpeg 2BF78844-565E-4212-83BA-010A9852DE82.jpeg
     
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  6. sdrawkcab

    sdrawkcab sdrawkcaB|Backwards Advanced User Premium Member

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    Interesting approach with the paint. I had wondered how well that would work. Curious to see how things turn out for you if you end up doing the entire plate.

    I was originally searching for more of a tinted cover, and stumbled across what I'm using now on eBay. I found this IR-reflective film that is adhered to a very thin piece of transparent plastic, precut for the size of a license plate. While plate covers are nothing new, these guys are the only ones I've come across that sell one that is IR specific. I got it installed and waited until nightfall, then used the IR-enabled security camera I have in my garage to test it. It works perfectly for IR cameras. I was really impressed. And it visually is almost not noticeable to the human eye. You'd really have to get up close to be able to tell anything was there. The plastic and film are so thin that they don't shift the color or light at all in the visual spectrum. I think I'll buy a few more for my friends for Christmas gifts next season :D FYI they make and sell a few different covers. Ones that are for visible-light flash to over-expose the image, and then the IR-only reflective cover. The IR one is visually crystal clear to the human eye, while their anti-flash over-exposure cover is more noticeable visually and has a very slight "blur" or "fog" side effect to it visually with the human eye when put on your plate.

    sunflex2010 on eBay - Sunflex's ebay page
    1pc lisence PLATE frame COVER anti red infrared light camera invisible cover | eBay - specific listing of their Anti-InfraRed covering.

    I'd definitely recommend the IR one. It exceeded my expectations. I'll see if I can find my photos I took of it in testing and share those. The one posted right here is not my vehicle -- it's one from their listing. But the pictures are accurate representations of what it looked like for me on my plate with the IR-only light. I can vouch for that.
    s-l500.png
     
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  7. PointerCone

    PointerCone M3 Kng Advanced User Premium Member

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    We’ve been around this block for years. @CJR238 and I considered using 3m white (clear) duct tape to some success and Veil has had limited benefit (very limited). You can either cover it or cause it to overexpose. Even Randy at No limits sells a electronic plate protector that may or may not work. Either way, this is a tough one.

    Benefits often do not equal return because cops are often triggered by anyone covering or messing with their plates. In IL, you can even use plate covers on front or back . Can Only use a frame, but no cover.
     
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  8. thanks

    thanks for all the fish Advanced User Acceptus Premium Member

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    BestRadarDetectors.net has the www.bestradardetectors.net: Ontrack IR Invisi-Plate Anti Infrared License Plate Protector. Blocks IR. Depending on lighting, it CAN block pictures that rely on IR. If you are looking for 100% good luck.

     
    Last edited: May 18, 2018
  9. Black16

    Black16 Learning to Drive General User

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    I havent really found any threads or research on this particular "block" as far as equiluminance on the plate surface using paint. Whether plate frames, plate covers, or duct tape...i didnt want to use any of those as they are way too obvious with little to no deniability. I wanted a solution that would not only potentially work, but allow me a comfortable level of deniability. A lot of it has to do with the plate itself and its design and some has to do with the paint i chose.

    Fortunately PA has a pretty good degree of freedom in the suburbs and rural areas. Unless you are doing something egregious, the police typically dont bother you. I already tempt them with window tint (havent been stopped in the 3 years I've had it) so I didnt want to with the plate with something so obvious as covering it with plastic or tape.

    I did consider sunflex, however, i didnt want to use a plate cover plan and simple. This whole project cost me a total of $67. $55 one time fee for the plate and $12 for the paint. If anyone has any good methods on how to test this beyond what I've tried or if in the southeastern PA area has the means to test this theory better, I am down to meet up and try.
     
    Last edited: May 18, 2018
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  10. kermudjin

    kermudjin Learning to Drive General User

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  11. drtoddw

    drtoddw Jammer bieten keinen 100 %-Schutz Advanced User Premium Member

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    Sticking a few leaves from a local tree with a dot of Elmer's glue would be cheaper and if caught, you could thank the officer for telling you and pull it off. During the winter, the can of "snow" used to decorate Christmas wreaths and such decorations looks like your plate was hit with salt. I've considered some clear spray paint that is highly reflective for just washing the whole plate out as well. They sell it for coating children's backpacks and painting a mailbox for finding one's driveway.
    ▪I will give credit to the plate with leaves to I post that I think I saw on flitservice.nl . I am, however, unable to find it.
     
    Last edited: Aug 20, 2018
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