Poor IR contrast in new Tennessee license plates

wittaj

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@EMPIRETECANDY - can you check with Dahua on if any cameras (especially the Z12E) are capable of talking to one of these units to sync shutter speed with the pulsed light? And if not, could that be a simple firmware update with one of the input/output wires?

 

wittaj

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As long as it doesn't look like a disco light LOL or like a misaligned floodlight blinding the driver, I think it would be ok?

Now I am wondering how close I can "misalign" my floodlight and get a color capture? I know what I will be trying tonight lol
So I "misaligned" one of my night chaser floodlights that has a more concentrated beam out into the street to see if that 2,700ish lumen spotlight could get plates in color.

Sadly it didn't work. I think the distance was just too great. It was close, but even with the car having a working plate bulb, still not possible.

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So I "misaligned" one of my night chaser floodlights that has a more concentrated beam out into the street to see if that 2,700ish lumen spotlight could get plates in color.

Sadly it didn't work. I think the distance was just too great. It was close, but even with the car having a working plate bulb, still not possible.
Unless you line up the LED light so that it is parallel to the direction of the camera, you'll see nothing. That might be your problem. I learned through trial and error just how sensitive the alignment was.
 

wittaj

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I am sure that is my problem as the floodlight and Z12E are not close to one another.

There is a "nuisance" house not too far from me. I say nuisance because it has so much junk in the yard, the porch, etc. that if it were in an incorporated area they would make him clean it up.

Anyway he has a camera that looks like a cheap Night Owl or something on his mailbox. At night, there is a light on next to it that doesn't blind a driver, but it is definitely visible. I am wondering if he has figured out how to do color LPR. He is down in a dark spot where there is zero ambient light except for this little light. I may see if I can stop by and see if he will talk to me.
 
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I performed some more experiments tonight, using a cheap LED flashlight I picked up at a trade show giveaway. You can purchase similar LED flashlights on Amazon for less than $5. I set the intensity to maximum and the beam width to the narrowest setting, which gave me a beam that covered the roadway pretty well at a distance of about 70 feet.

Below are two plate captures with the flashlight positioned just beneath my -Z12E camera, parallel to its direction. I captured both an old plate and new plate for comparison. Overall, I was impressed how well it worked.

But there's one major drawback: the beam is too bright. I wouldn't say that it would blind a driver, but it would definitely be distracting. Some type of pulse-width modulation will be necessary to solve that problem. Reducing the "apparent" intensity to 10% or 20% of maximum should make it tolerable.

IMG_9353.jpgScreen Shot 2022-09-06 at 9.16.38 PM.pngScreen Shot 2022-09-06 at 9.16.10 PM.png
 
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wittaj

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Doing some research and seeing if I can find any stories about these new plates and see that you have already been hard at work dealing with the media!


 
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Latest update: I am purchasing an LED kit from LEDsupply.com with the goal of modifying it for LPR nighttime color capture. I'll use an NE555 timer board to experiment with different duty cycles for the LED. I won't be certain until I have the kit in hand, but I think that I should be able to mount it directly underneath one of my -Z12E cameras. It will run on 12 VDC, which I can either supply from a separate adapter or by down-converting the DC voltage from the PoE cable supplying the camera.

If this works as well as I hope it does, it will solve my problem of nighttime LPR capture with the new Tennessee plates. But beyond that, I'm now wondering if a similar light set to wide beam might also improve the nighttime performance of my 5442 camera pointing at the street. We shall see.
 

samplenhold

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But beyond that, I'm now wondering if a similar light set to wide beam might also improve the nighttime performance of my 5442 camera pointing at the street. We shall see.
I am very interested in what you come up with on that. Also, once you get this working, please, please give a post of how you did it.
 

wittaj

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If it works, you will have to make a demo and ship it around the country to us to give it a try with our install LOL.

How critical do you think it being close to the camera is? Where my camera is on the 2nd floor, the white light would look obvious and out of place, but I could locate the light down on the first floor on the same horizontal target line and hoping that at 175 feet out for the plate that a 10-12 height difference between the camera and light wouldn't be an issue?
 
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If it works, you will have to make a demo and ship it around the country to us to give it a try with our install LOL.

How critical do you think it being close to the camera is? Where my camera is on the 2nd floor, the white light would look obvious and out of place, but I could locate the light down on the first floor on the same horizontal target line and hoping that at 175 feet out for the plate that a 10-12 height difference between the camera and light wouldn't be an issue?
In my experiments, it was absolutely essential that the LED be placed parallel to the camera lens, and very close to the camera. In my case I plan to mount the illuminator directly beneath the camera. It should be small and lightweight.
 

wittaj

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In my experiments, it was absolutely essential that the LED be placed parallel to the camera lens, and very close to the camera. In my case I plan to mount the illuminator directly beneath the camera. It should be small and lightweight.
I can definitely get it parallel, just 12 feet apart in vertical distance LOL. I wonder if that would make a difference compared to it being off to the side a few feet? One would think the white light wouldn't be as sensitive to the angle as the IR is, but your limited testing indicated it does make a difference.

ETA on when the parts will arrive or is this like the bulb you tried that it will get there when it gets there?
 
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I can definitely get it parallel, just 12 feet apart in vertical distance LOL. I wonder if that would make a difference compared to it being off to the side a few feet? One would think the white light wouldn't be as sensitive to the angle as the IR is, but your limited testing indicated it does make a difference.

ETA on when the parts will arrive or is this like the bulb you tried that it will get there when it gets there?
The LED lamp kit arrives this Saturday. After that I'll start some tests, beginning at full duty cycle with various beam widths and lens types, and see how it performs. I'll keep everyone updated as my testing progresses.
 
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I can definitely get it parallel, just 12 feet apart in vertical distance LOL. I wonder if that would make a difference compared to it being off to the side a few feet? One would think the white light wouldn't be as sensitive to the angle as the IR is, but your limited testing indicated it does make a difference.

ETA on when the parts will arrive or is this like the bulb you tried that it will get there when it gets there?
It could be that a greater distance from the camera is possible. I found it easiest to brace the flashlight against the camera body to ensure that it was parallel, but very careful aiming from several feet away may still provide good results. I will leave that to someone else to try.
 

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Eagerly awaiting test results, especially for general LPR captures at ~190 feet. My Z12's red eyeballs stand out a bit at night, and having a low intensity white light would be great.
 
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Any luck?
I've received the parts, but haven't had a chance to experiment due to a water leak in my office that forced me to disassemble my work benches and move my equipment out of the way. I'm hoping to take a stab at it sometime next week once the area has been dried out and I can move one of my benches back in place.

I'm certain I can make it work; it's more a matter of figuring out the optimum configuration.
 

jayden.donaldson

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I've received the parts, but haven't had a chance to experiment due to a water leak in my office that forced me to disassemble my work benches and move my equipment out of the way. I'm hoping to take a stab at it sometime next week once the area has been dried out and I can move one of my benches back in place.

I'm certain I can make it work; it's more a matter of figuring out the optimum configuration.
FYI, kentucky plates are doing the same thing. I'll try and dig up a few samples
 
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