Poor IR contrast in new Tennessee license plates

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sebastiantombs said:
Being a skeptical cynic and part time conspiracy theorist I have to wonder if this isn't the end goal, making LPR by the "normal citizen" more difficult or impossible? LEO will adopt to whatever it takes, they're funded by the "normal citizen". Then again there's the defund/weaken the police movement going on, too. Just letting what passes for my mind wander a little.
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Even if true, it's a strategy that is doomed to failure. LEO may adapt, although it will cost them more money to do so. But by the same token, private citizens can still purchase cameras that are every bit as good as what the government is buying. I can assure you that you have better optics on your camera than Flock Safety does.

There's no special sauce that government can build into LPR systems that can't be replicated in the private sector. There's nothing prohibitively difficult about switching to different wavelength IR systems, beyond the inconvenience. If we see a big wave of states switching to "unreadable" plates, then I expect that 740nm LED illumination will become an increasingly common option for varifocal cameras.
 
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wtimothyholman said:
It's a great way for states to increase revenue with dozens of specialty plates.
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Wow, I never came close to connecting those dots. I tried to count how many different plates Oregon has but there are so many I didn't get an accurate count. I think it's in the 40 ballpark. This is the one I for sure can't read:
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tigerwillow1 said:
Wow, I never came close to connecting those dots. I tried to count how many different plates Oregon has but there are so many I didn't get an accurate count. I think it's in the 40 ballpark. This is the one I for sure can't read:
View attachment 123361
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If Oregon is like Tennessee, what you'll find is that black lettering shows up, but plates with white lettering (or other colors) will not.
 
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Toll roads probably do not use IR. Every one I have been on at night are well lit and use a flash as you drive under them.
 
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Lotta hardware up there don't nknow what it all is. d546c55daa274781e6a7670e9a9b65e3.jpg
 
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Yeah strobes are used for tolls I’ve seen on the Fl turnpike. LPR IR tech is more for stealth detection. Not nearly as obtrusive as pulsed strobes but not as good at reading plates either.
 
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biggen said:
Yeah strobes are used for tolls I’ve seen on the Fl turnpike. LPR IR tech is more for stealth detection. Not nearly as obtrusive as pulsed strobes but not as good at reading plates either.
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On the other hand, companies like Genetec have used strobed 740nm illuminators on some LPR cameras to get multiple levels of exposure. Stealth really isn't as much of an issue on an interstate or along a major road in a city. It wouldn't surprise me if the strobed illuminators on toll roads also included infrared sources.
 
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tigerwillow1 said:
Wow, I never came close to connecting those dots. I tried to count how many different plates Oregon has but there are so many I didn't get an accurate count. I think it's in the 40 ballpark. This is the one I for sure can't read:
View attachment 123361
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And by the way, here's how to tell that it's a 3M tag: look closely for a thin vertical double spiral "thread" running down the center of the plate. That's 3M's anti-counterfeiting watermark. The problem with printed plates is that someone with a good color printer could produce a passable fake plate without much effort. The watermark allows LEOs to tell at a glance if the plate is real.
 
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Yeah I've got those "spiral Threads" on my Minnesota plates.
 
wtimothyholman said:
And by the way, here's how to tell that it's a 3M tag: look closely for a thin vertical double spiral "thread" running down the center of the plate. That's 3M's anti-counterfeiting watermark. The problem with printed plates is that someone with a good color printer could produce a passable fake plate without much effort. The watermark allows LEOs to tell at a glance if the plate is real.
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Some of our Texas plates have them, and some do not. It is two threads in Texas.


1648403986434.png
 
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Well, there's good news and bad news in my latest update.

I purchased a Nightfox XB 940nm 5 W flashlight, for two reasons: to see how sensitive my Dahua -Z12 varifocal cameras would be to 940 nm IR light, and to see if the reflectivity of the new TN plates would be substantially different at 940 nm versus 850 nm. If so, it would be far better and easier to set up 940nm illuminators as opposed to 740nm illuminators.

The good news: my cameras had no difficulty detecting the 940nm IR flashlight. It was very bright, which would indicate to me that the difficulty was with trying to use the "grow bulbs" as 730nm light sources. The 740nm illuminator I have on order should work far better.

The bad news: if anything, the contrast of the plates under 940nm IR light was even worse than with 850 nm IR. So IR illuminators in the range of 730 nm to 750 nm will be mandatory to view the new TN plates.
 
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Thanks for all your testing.

The 940nm having trouble with the plates doesn't surprise me.

If possible, have you tried turning your PTZ to the location of the plates to get more IR on the plate for the Z12E to see?

Is there ETA on your 730 illuminator?
 
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wittaj said:
Thanks for all your testing.

The 940nm having trouble with the plates doesn't surprise me.

If possible, have you tried turning your PTZ to the location of the plates to get more IR on the plate for the Z12E to see?

Is there ETA on your 730 illuminator?
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Supposedly the 740nm illuminator should arrive by next week at the latest.

As to the PTZ, I haven't tried that. I'm not sure it would make any difference, as I've done plenty of testing using a portable IR camera with 850nm IR. The contrast isn't helped one bit by higher intensity 850nm IR light.
 
Bummer. I don't see many new plates yet, so you are ahead of the game that will help us all, but I recently was experimenting with putting my PTZ into infrared instead of color. My neighbors recently took down some trees so the range is now greatly expanded but needs to be IR. I tested it and was surprised how much more pop the plates had with that extra light, but figured it probably wouldn't help the new plates much and I just thought about that with you.
 
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