Does all of this apply even if the cars will only be driving 30mph max? This particular area isn't practical to drive any faster, even if you're wanting to burn rubber, because the roads are narrow and short.
Need LPR advice
- Thread starter ArmoredDragon
- Start date
Yes, LPR is an art more than it is a science. Whether the car is traveling 15mph or 60mph, unless you have stadium quality lighting, you need a fast shutter to counter the reflectivity of the plate when using infrared.
Otherwise the plate is washed out with IR like this for a car not moving...
You will need a minimum of 1/1,000 shutter, but most run 1/2,000 shutter at night. The faster the shutter, the more light that is needed. That is why the image is all black except for the head/tail light and plate because we are taking advantage of the reflectivity of the plate.
In a few perfect situations where there is enough light and cars come to a stop sign or are barely moving, you may get by with a 1/250 shutter, but that shutter speed will not cut it at 30mph. At 30mph you will probably need 1/1500 or 1/2,000 and it will be a black image.
Otherwise the plate is washed out with IR like this for a car not moving...
You will need a minimum of 1/1,000 shutter, but most run 1/2,000 shutter at night. The faster the shutter, the more light that is needed. That is why the image is all black except for the head/tail light and plate because we are taking advantage of the reflectivity of the plate.
In a few perfect situations where there is enough light and cars come to a stop sign or are barely moving, you may get by with a 1/250 shutter, but that shutter speed will not cut it at 30mph. At 30mph you will probably need 1/1500 or 1/2,000 and it will be a black image.
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Flintstone61
Known around here
Flintstone61
Known around here
Flintstone61
Known around here
I find using 2 cameras to film the same location works well. Albeit my overview cam could be a little better model.
Wait how is it that the HFW5241E-Z12E does so well with a 1/2.8" sensor? I thought the standard these days was 1/1.8"? My current cameras have that and do remarkably well, especially considering they have a 111 degree FOV and still managed to catch the last two letters of that plate from 50 feet away (which was pretty impressive IMO considering that's not what they're intended for.)
I'm guessing the only reason the IPC-B5442E-Z4E is inferior because of its shorter maximum zoom range?
I'm guessing the only reason the IPC-B5442E-Z4E is inferior because of its shorter maximum zoom range?
Flintstone61
Known around here
Possibly, I don't know if that was their routine, just speculation on my part. Given they got a u-haul truck, I think it's unlikely they wouldn't have it planned out in some way. Curious whether the truck was rented or stolen.
For plate reading, or any IDENTIFY at distance, focal length is more important than MP. I linked a thread I did previously showing how a D1 resolution at the right focal length can capture plates.
2MP on the 1/2.8" sensor is an ideal MP/sensor ratio, just as 4MP on the 1/1.8" sensor is an ideal MP/sensor ratio.
The reason most opt for the Z12E is because it's optical zoom is double that of the Z4E that has half the optical zoom. The goal is to get clean capture of plates without having to digital zoom and guess.
Look - you luckily caught two letters of the plate from 50 feet away in the daytime from a slow moving vehicle with some digital zoom and guessing. Daytime on a slow moving vehicle is ideal conditions. How many robberies are going to be under ideal conditions in the daytime with a rented U-Haul pickup. Tell me how many you get at night. Can you get any letters of a plate of a vehicle going by at night with your current cameras?
What do you want, partial plates or the whole plate? Do you want to digital zoom and still have to guess or have an optical zoom and take the quess work out of it?
There is an entire subforum dedicated to capturing plates. If it could be done reliably and consistently with cheap 4K 2.8mm fixed lens Lorex cameras on a less than ideal MP/sensor ratio, do you think any of us would waste our time and money buying another camera and tweaking it just to capture plates? Sure some of my overview cams under ideal daytime conditions can capture plates with a lot of digital zoom and some guessing, but forget about it at night.
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looney2ns
IPCT Contributor
You need to take an afternoon, and read the links already provided to you. That will answer your questions.
You have the perfect place out in your front yard for LPR cams.
Read this: New to LPR? Considerations Before You Begin | IP Cam Talk
And read it, don't just skim through it.
You have the perfect place out in your front yard for LPR cams.
Read this: New to LPR? Considerations Before You Begin | IP Cam Talk
And read it, don't just skim through it.
Shutter speed is what will freeze the plate. Thirty MPH is pretty fast for a camera at an angle and at some distance. Yes on toll roads there are cams that grab plates doing 80mph, but they are directly over the car about 15 feet high and are well lit, usually with a flash at night.
These cams are not much different that a DSLR camera like a Nikon D700. every photographic rule applies to both cams. IP cams are not some magic weapon. Read the links provided and then come back and ask questions. If you are not willing to take the advice given here, then why ask for it?
That cam is not 'inferior'. It is a cam that is quite nice. I have one doing overview and vehicle ID at an intersection and it does it's assigned tasks quite well. I run it in color 24/7 and get some plates during the day. If the angle is just right I get some plates at night. But that is not the task I have assigned to it.
Each cam in your arsenal needs to have a purpose. My 5241 Z12 cams are for LPR only. They were picked based on the distance, angle and long IR reach. They are perfect for my LPR cams. All of my cams were picked based on what the job was for that view. I would not pick that cam to be placed at my front door to get a face shot of someone withing 10 feet of my door. That would not be a good fit for that cam's abilities. Just like I would not pick a T5442TM-AS in 2.8mm as an LPR cam for targets 80 feet out and 35 degree angle.
Not quite as straight forward as it might seem. In Arizona, only the rear plate is required. For the direction that truck went, there are a few places I could get away with. For the other direction, not so much. Per the HOA rules, no wiring can be visible. In addition, there's a big tree in that direction in my front yard. Both of these things complicate the situation.
Also I'm just about out of room for more cameras in my NVR, so I've got that to consider as well (there are too many things to list that I don't like about blue iris, chief among them that it requires a dedicated desktop computer.)
What is an NVR but a watered down desktop computer... most here spent less on a BI computer than a real NVR....
Check the thread @samplenhold put together where he hid them in a hose reel type device.
Check the thread @samplenhold put together where he hid them in a hose reel type device.
If it could run under VMWare that would be fine, though I've heard there are all sorts of problems with that. But the overall design of the program and many other things about it I just really don't like. Though most NVRs I've seen are equally bad if not worse.
Actually Moonfire NVR is looking interesting, but mainly from my perspective as a rust developer.
Actually Moonfire NVR is looking interesting, but mainly from my perspective as a rust developer.
Again, it depends on the parameters for LPR: distance, angle, and lighting/IR need. Here are two examples, one daytime, one nighttime. The caps marked LPR East are from my 5241Z12 and the ones marked Intersection are from my B5442 Z4 cam. Same car, same time.
And like an infomercial lol, @samplenhold color results are not typical and your results may vary lol.
He has great lighting and an intersection where cars slow down a lot and great Texas plates!
And even so, he runs a b/w LPR as his color won't get every plate.
He has great lighting and an intersection where cars slow down a lot and great Texas plates!
And even so, he runs a b/w LPR as his color won't get every plate.
Point being that the B5442 Z4 is not 'inferior' for LPR. It all depends on the parameters of Distance, Angle, and Lighting. That 5442 Z4 does a great job in B&W with IR on. I just do not run it that way because that is not the job it is tasked to do.
Now as I hit 'post reply' and wait for the browser to work...
EDIT: OK, what just happened? The browser refreshed immediately?
Exactly! My 5442-Z4E is used the same way as a tighter color overview.
Could I convert it to LPR duty, yes, but at 55 feet I was guessing and digital zooming more than I would like.
And I don't have the angle or light you do so a car would have to stop for me to get a plate in color.
Could I convert it to LPR duty, yes, but at 55 feet I was guessing and digital zooming more than I would like.
And I don't have the angle or light you do so a car would have to stop for me to get a plate in color.
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