Night Settings for LPR - Dahua Z12E

Y

YouHF

n3wb
Aug 1, 2015
12
7
I've had a IPC-HFW5241E-Z12E for a few weeks and while it is crisp in the daytime, I've had absolutely no luck at night. Can some of you share your settings for night time LPR in a dark scene? I've tried many combinations of settings without much luck. My other LPR camera (HFW5242H-Z6E-MF) is doing well at night under similar conditions.

The HLC seems to be what is introducing the major artifacts, but without it I'm not getting much better in terms of plate captures. I've tried at 1/500 as well as 1/2000 without much improvement. Suggestions?

Here is daytime (very happy with results):
1606891248270.png

Here is an example of what I'm getting at night (and before you ask, this was at 1/2000):

1606890942292.png
with:
1606891325508.png1606891340220.png1606891367386.png1606891387264.png





At best, this is about as good as I've got:
1606892651947.png
with these settings:
1606892680142.png1606892686501.png1606892694632.png1606892700656.png
 

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After just trying something I wonder if I have a defective unit - check out the difference between B&W vs. color with otherwise the same settings (this is 1/30):
1606893534613.png

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1- For one thing, your DNR is way too high. Anything more than about 40 and you'll get the blur your seeing

2- try manual fixed shutter not shutter priority

3 Also try 50 on Exposure Compensation and about 60 on Iris, go back to 50 on Gamma

4- At 1/2000 you shouldnt need much HLC, but if you do try to keep it under 50

5- Bitrate shoud be as high as you're comfortable with. I run 8192, no less than 4096

My settings at 90-100ft
LPR-Z12-1.jpg LPR-Z12-2.jpg LPR-Z12-3.jpg LPR-Z12-4.jpg

HOA Entr_EntrTag_main_20201201180715_@3.jpg
 
Last edited:
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You also need to change exposure to MANUAL and not shutter priority as you need to turn the gain way down. Using shutter priority allows the camera to max out the gain in order to see an image and that is what you are getting.

Looks like you are also getting IR bounce off something above the camera.

Also looks like bitrate is too low.
 
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Interesting you turn your sharpness down so far, I do get some pixelization on my 4MP 1/2.8 sensor on the new ptz (though not on my 2MP 5231) , I may try that tonight

Is yours a 4MP?
 
I was going to say "Man your sharpness is low!" when I read it this morning.
 
I going to try lowering mine tonight and see if it makes a difference as well.
 
Hi,

I know an old thread but as such knowledge shown above I thought would ask here, ref. LPR

Just got a lesser Dahua DH-IPC-HFW2531S-S-S2.

Cheapo generic almost worked so did not think had to go higher up the cost.
Excellent daylight & just about working night time but yet to fiddle with settings.

Tricky as so few cars come at night that I can test & my better half is fed up driving in & out for some other testing I did so would really like a good starting point before I bother her again.

Is quite a well lit area, small flood in front of car & tall lamp behind so real life about as bright as the image shows.
default settings but I do force the colour (As did work better on the generic)

I am happy to leave on IR auto, which just about switched to B/W, if likely get better LPR.

As car is down to a few mph does grab the plate but only just, before its angle is too acute to read. I really prefer to keep this angle for the camera to get the area overall.

Since the image below have pointed it out fractionally & angled so plate is pretty much horizonal.
Want to reduce the motion blur, I guess trying to manually do the shutter? if I raise past 2000 it gets very dark, goes B/W and not sure what/if any settings to compensate.
I can increase the lighting quite easily but wonder if might simply get more glare from the car.


DahuaLPR.jpg
 
Hi,

Thanks for your very fast response.

DNR was 50,
Should I try grade 30 ?

Was auto, shall I try shutter priority first as quite well lit, I know someone above said manual but they seemed to be for almost dark B/W scenes and wonder if a good compromise for a half decent normal (non-LPR) image. Will try 1/500 anyway.

LPR is the most important but also would like to general security viewing.
 
Stay away from shutter priority. Use manual, start at say 1/120 and keep increasing until you see the blur go away. DNR 35-40 should help.

At some point you may have to decide if you want clear legible plates or color. Lots of factors go into this, not the least being how much ambient light you need to maintain color and still mitigate blur.
 
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Regarding a camera for plates (LPR) - keep in mind that this is a camera dedicated to plates and not an overview camera also. It is as much an art as it is a science. If you want to capture plates, you need a camera just for that.

During daytime it may act as an overview, but at night the shutter tends to need to be faster to capture the plate, and the faster the shutter, the darker the image.

Most of us run B/W to take advantage of the reflective properties of a plate which is why we can run a faster shutter to get the plates. Once you decide to keep it in color, the shutter speed slows way down and might not be fast enough to actually capture a plate.

You may have enough light and the car moving slower to capture, but you may also need to decide what is more important - the overview or the plate. Most of us run two cameras.

At night, we have to run a very fast shutter speed (1/2,000) and in B/W with IR and the image will be black. All you will see are head/tail lights and the plate. Some people can get away with color if they have enough street lights, but most of us cannot. Here is a representative sample of plates I get at night of vehicles traveling about 45MPH at 175 feet from my 2MP camera (that is all that is needed for plates):

1634400792955.png

And then I have another camera that is used to capture the color and overview properties that run at a slower shutter.
 
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Many thanks to all of you,

going to try Manual 1/125 or 1/250, DNR 35 & keep colour for the moment.

Trying to avoid 2 camera's mainly because only have 1 cable, 50m from house & JUST managed to get 1 fed down conduit.
Do have power but prefer not to box more power socket & switch as will look a mess on my gate which already has too much with the electric gate unit & control.

Is well lit & I can add another small flood.
The car is slowing as coming up to the gate so not like passing vehicles,

Either way I think going to be great as sure LPR will work well at night, ideally in colour with overview but if not that will be OK also.

Just for ref. using PlateReconiser SDK, they did me a custom pricing, which surprised me. not sure if to mention price but under $10 for 10k plates.
the free 2500 would have done during the day but even with good camera & LPR ability it needs a good few images at night but will see how it goes.
I needed local access to the plate data to open the gate, OpenAPR is not guaranteed to continue the webhook access, they actually told me it was a quirk & I should not be able to access cloud data direct.
 
bignose3 said:
Many thanks to all of you,

going to try Manual 1/125 or 1/250, DNR 35 & keep colour for the moment.

Trying to avoid 2 camera's mainly because only have 1 cable, 50m from house & JUST managed to get 1 fed down conduit.
Do have power but prefer not to box more power socket & switch as will look a mess on my gate which already has too much with the electric gate unit & control.

Is well lit & I can add another small flood.
The car is slowing as coming up to the gate so not like passing vehicles,

Either way I think going to be great as sure LPR will work well at night, ideally in colour with overview but if not that will be OK also.

Just for ref. using PlateReconiser SDK, they did me a custom pricing, which surprised me. not sure if to mention price but under $10 for 10k plates.
the free 2500 would have done during the day but even with good camera & LPR ability it needs a good few images at night but will see how it goes.
I needed local access to the plate data to open the gate, OpenAPR is not guaranteed to continue the webhook access, they actually told me it was a quirk & I should not be able to access cloud data direct.
Click to expand...

Are you using Blue Iris? If so, you can set up the motions and what not to eliminate the false to get you under the 2500 maybe.

Many of us use this adapter and works very well and allows you to have one cable feed but two cameras. Many people have this serving the LPR and overview camera.

 
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