IPC-HFW5241E-Z12E LPR Night time problem

[eeeeesh]

I have a IPC-HFW5241E-Z12E from Andy that is about 2 months old and from time to time I am seeing a problem with my night time videos. It is kind of hard to explain, but it is almost if there was a 'mask' of some sort that blocks the view, but there are clear spots where previous cars have passed by (almost like tracks) which appear to be caused by their tail lights

So the camera is setup to catch license plates as they make a 90 degree right hand turn about 70' away.

daytime view:


Nighttime, but I edited the screen grab by increasing the exposure so you can see the 'tracks' (lighter areas) more easily. The darker areas (the mask) blocks the view of anything behind it. A car is just entering the area


This is the same photo without any editing - You can barely make out the tracks if you look closely.


Here the car has moved forward and you can clearly see the license plate and it is in one of the clear 'tracks' area


The car and the plate are now about 90 degrees to the camera, usually the 'sweet spot' to get a good pic of the plate, but you can see that the plate is being masked by something - and yes I just cleaned the lens several hours beforehand. The taillights are clearly visible because I think they are creating the clear 'track'



video
View attachment LPR Mask.mp4

 

[Parley]

Let me just say that I have that camera in black and white for both day and night. The only purpose I am using it for is license plate numbers like you are. I find that having the plate at and angle gives the best view of the numbers at night like in your 4th picture. Not head on like you are showing in your 5th picture. I assume it is the lighting and the color mode that is causing the problem.

 

[wittaj]

Same here I am B&W.

Send some screenshots of your settings - shutter, gain, noise, etc.

It almost appears like a "burn-in" of the typical vehicle route, but hopefully it is simply a setting that needs adjusted as something is off and magnifying the traffic route in the road.

 

[eeeeesh]

Well, I thought I had the profile set to 'automatic', but now I see there is another tab 'profile management' that was set to full-time 'day'. Maybe that was my problem?

Here are the night settings

 

[wittaj]

That could very well be the problem. I would try setting the night profile to B&W and see if that takes care of the problem tonight.

What are your day settings? to get a color pic of plates is impressive because it doesn't appear you have any ambient light from those photos.

 

[eeeeesh]

My day time settings are pretty generic and you are right, there is not much ambient light at night. Basically the entire picture is black until a car comes into view. I live on a fairly short dead-end street. There are only 5 houses past our house and with Covid 19, there was not very much traffic at night but things are starting to pick up. I think I will first see if the day/night thing makes a difference first. Thanks wittaj and Parley for your help

 

[mech]

Also set the I-frame Interval to the lowest interval that you can. What bitrate are you using?

 

[wittaj]

I am wondering if something else is happening there. 1/10,000 shutter at night with no ambient light should not pick up in color without a LOT of ambient light. I don't think a license plate light bulb would be bright enough. That high 3D NR would certainly cause the "ghosting" if for some reason you can pick up color plates at 1/10,000 shutter and not lose focus.

 

[eeeeesh]

I am using the Dahua Sunrise/Sunset utility to manually set the focus and zoom. And yes, 15 iframe and fps on all my cams

 

[wittaj]

Oh ok with that utility it needs to be set to full time day. That utility will then pull the day or night time zoom and focus at the time required and switch from day to night mode.

Your night settings look good regarding shutter and noise. Try setting night to B/W instead of auto and see if that fixes it. Still surprised it would auto color at night with 1/2000 shutter speed.

 

[eeeeesh]

Well, I guess that is why I had the profile setting to 'full time day' (post 4) - I didn't remember why, lol

So I will change it back to 'full time day', night to B &W and leave day on auto

 

[wittaj]

That should do it - but the focus for B/W will be different than color, so you will need to put the camera in B/W mode while light out to get that focus number.

 

[eeeeesh]

I didn't think the focus would change? I will have to do it tomorrow, thx (or hopefully it will work ok tonight)

 

[wittaj]

I guess see it tonight and see what happens. I have one cam that the focus is almost the same between b/w and color and another it is off a lot. Each circumstance is different, but that was one of the benefits of the utility you use was to allow folks using this came for LPR to get that different focus for night time.

 

[wittaj]

Did you get this figured out? I am curious to see how you got those plates at night in color at that shutter speed.

 

[eeeeesh]

I kind of forgot about - I am only getting one at the most, two cars at night, but thanks for bringing it up again. So this is with the utility set to full-time day, day mode set to color and night to black and white. It's readable, but I have had better in the past and I need to tweak the settings some more. I think 'color' was causing the problems at night. I am going to change it to color and see what happens tonight.



Everyone cuts the corner when they drive past my house, so I can get the front plate also, if they have one

 

[wittaj]

Looking a lot better! Looks like gain and or noise is up a little too high, but a big improvement.

 

[pozzello]

for plates at night, crank up the IR as much as possible and reduce DNR as much as possible to minimize ghosting

 

[eeeeesh]

It definitely appears to be from using color mode at night. I can get a good plate - in between the tracks/burn-in

 

[wittaj]

That is crazy you are getting color at 1/2000 shutter - and there is no ambient light there helping?