Lpr cam help hopefully last time

S

sdiamond808

Getting the hang of it
Jul 2, 2017
118
14
First you all helped me so much get this thing tuned. I wanted to start capturing plates from the street vs who pulled in my drive way.

DS-2CD7A26G0/P-IZHS is the camera I am using.

I know the angle is not ideal but during the day it captures everything. Distance between 100-110 feet. Camera says it can handle that distance, although close to the max and daytime looks good.

Issue is at night I am not capturing plates. I attached a picture of what I'm getting. I'm at 1/1000 exposure. What can I adjust to make this better?
 

Attachments

  • Screenshot_20230810_090032.jpg
    Screenshot_20230810_090032.jpg
    422.3 KB · Views: 59
That is a focus issue (plus I don't think enough zoom for night)

Daytime and nighttime with infrared can be different focuses.

And since the image is so dark, the camera cannot see anything to focus on, so it hunts all night and results in blurry image that you have here.

You need to either run 24/7 B/W, switch night profile to manual focus and park a car in the field of view to get a good focus at night, or put it on a schedule and change the night profile while there is still enough light for it to find a focus.

Now with that said, a 12mm zoom at 100 feet probably isn't enough zoom for night captures. Most of us have only seen 12mm able to capture plates up to around 40 feet. Please keep us posted.
 
  • Like
Reactions: Parley
For plates, the IR illuminator would have to be right next to the camera as plates reflect back light in the direction it came from. So it could actually wash out the plate and make it worse if too far away.

Post a pic of your daytime - I suspect you have to DIGITAL zoom to read the plate? If so, night time is going to be problematic.

You really need more OPTICAL zoom at 100 feet.
 
  • Like
Reactions: Parley
Trash cans aren't normally there. It picks up plates during the day and stores them just fine
 

Attachments

  • Screenshot_20230810_103004.jpg
    Screenshot_20230810_103004.jpg
    1.7 MB · Views: 43
I mean let us see a car with plates in the image LOL

But given how blurry the lettering is on the garbage cans, I would say there is digital zoom and some guessing going on to read the plates.
 
  • Like
Reactions: Parley and bigredfish
wittaj said:
I mean let us see a car with plates in the image LOL

But given how blurry the lettering is on the garbage cans, I would say there is digital zoom and some guessing going on to read the plates.
Click to expand...
I don't think I'm digitally zooming? I go to the ptz function on the cameras we've interface and click zoom in. Is that how the varifocal lens works?
 
So you can read the plate in that field of view without zooming in?

Based on that image I don't think it can be read without digital zooming.

But please post an image with a plate in it for us to see.
 
wittaj said:
So you can read the plate in that field of view without zooming in?

Based on that image I don't think it can be read without digital zooming.

But please post an image with a plate in it for us to see.
Click to expand...
I have to zoom to read the plate but it's a 2.8mm to 12mm varifocal. That means I have optical zoom I think. Waiting to catch a plate then I will post
 
I agree that a camera with more zoom capability might be required here. As wittaj has pointed out, if you can't clearly read the letting on the trashcans, you are going to have a hard time clearly reading plates - especially in low/no light. We always suggest using manual focus for this, but again as wittaj mentioned, the actual focus numbers will change between daylight and low/no light due to the IR filter. You'll have to dial in the actual manual focus during the day and then again at night. The easiest way to do this is to park a car so it's license plate is in the "sweet spot" and then dial the focus and exposure settings in.
 
  • Like
Reactions: Parley
The Automation Guy said:
I agree that a camera with more zoom capability might be required here. As wittaj has pointed out, if you can't clearly read the letting on the trashcans, you are going to have a hard time clearly reading plates - especially in low/no light. We always suggest using manual focus for this, but again as wittaj mentioned, the actual focus numbers will change between daylight and low/no light due to the IR filter. You'll have to dial in the actual manual focus during the day and then again at night. The easiest way to do this is to park a car so it's license plate is in the "sweet spot" and then dial the focus and exposure settings in.
Click to expand...
Manual focus is on the ptz menu right? It's a varifocal lens so I know it zooms
 
If the camera is already optically zoomed to 12mm (meaning that image above is already optically zoomed to 12mm) and you do additional zoom after that, then that is digital zoom and that will be problematic at night.
 
Last edited:
wittaj said:
If the camera is already optically zoomed to 12mm (meaning that image above is already optically zoomed to 12mm) and you do additional zoom after that, then that is digital zoom and that will be problematic at night.
Click to expand...
No additional zoom, just optical. Shouldn't 12mm lens be able to see 100-110 feet away?
 
Not plates unless they are the size of a bumper lol.

Again can you please post an image of with a car in image for us to see ourselves that we can read a plate at that field of view without having to zoom in. I don't think it is possible especially given I can't read the lettering on the trash can and even zooming in it is more guess than confidence.

We have seen 12mm to read plates maxes out at 40ish feet. Folks are using 64mm to read plates at 110 feet.
 
  • Like
Reactions: bigredfish, Parley and actran
My 5442 varifocal set to the max zoom of 12mm. The license plate on the blue car across the street is approximately 106 feet away and the white car is 100 feet away.

Double_Bay 2023-07-09 09.55.30.290 AM.jpg
 
  • Like
Reactions: bigredfish
sdiamond808 said:
Here is the picture. Not as clear as I would like. What do I need to do?
Click to expand...

Dusk and Dawn captures are always the most difficult.

But like we have said, you need more zoom. Especially at night.

I have to take that image and hit the magnifying glass (which is digital zoom) to make the plate bigger so that I can attempt to read it and even then it is guessing more of the characters than it is accurate.

Compare that to an OPTICALLY zoomed camera set up to make the plate as large as possible.

1691850033144.png


Ideally the field of view should be no larger than the size of the vehicle, even more so when you have a less than ideal angle like you do.

You really need it zoomed in to about the area in red, which means a different camera. Who cares if the marketing said you can get 110 feet with 12mm....that is under ideal perfect conditions like straight on and not moving...real world shows 12mm at 110 feet is problematic for accurate plates.

Real world experience indicates whatever distances cameras claim, you have to cut it in half during the day and cut that number in half for night time.

1691850224181.png
 
You must log in or register to reply here.
Top Bottom