clearer capture of lic plates?

[coworkerbob]

Hello,
our neighbor's house got broken into and i submitted footage to the police. I have 3mp dahua 3.6mm lens kit from costco. I am thinking of swapping my cameras pointed at the street to get a clearer picture of car plates parked on my side street. Would a higher res 4k or 12mm lens or varifocal would have captured better plates? I'm trying to balance seeing my windows, fence, and sideyard and the street but i looks like you have to choose one over the other.

 

[tangent]

Yes a tighter FOV or good higher res camera would have probably got a bit more detail. However, LPR generally requires a dedicated camera and for ALPR the angle to the car in that position looks too steep. A camera with a tighter fov would need to look farther down the street. A dedicated camera is required at night to you can set a high enough shutter speed to capture something other than a washed out image.

There's still enough detail in your capture to help to police

 

[bababouy]

If this car is parked, or if a car parks in the range of this camera, and it during the day, then you should be good with a capture that is closer to the street. If there are any other conditions, then follow @tangent guidelines. It would almost work it you mounted a camera on the fence. Is this in Califonia? the tag looks like a CA tag.

 

[coworkerbob]

Yes, Ca license plates. Suspects circled 8 - 10 times before pulling up to my side of the street. I was reading up in the other threads here... Alot to think about, 4k might do well in the day but give too much noise at night. Too bad costco doesnt carry the 2mp dahua starlight cams for me to test out. Here is a shot the other way around where i could point the camera at the street as all cars come to a stop or turn the corner to drive onto the side street. I can almost make out the license plates from the different angles and frames.

 

[coworkerbob]

Thank you for the great suggestions tangent & bababouy.

 

[bababouy]

The height of the camera makes a huge difference in the capture also. You want to get as close to "directly behind the car and the same height as the license plate" as possible. I would consider a small box on the fence that is inconspicuous, mounted about 4ft off of the ground, so that the camera is protected. this is tough to pull off but can be very effective for license plate capture.

 

[Fastb]

Would a higher res 4k or varifocal have captured better plates?

Higher res will have poorer images in low light.
Work on getting good low light pics first. Then the daylight results will almost certainly be acceptable.
Varifocal doesn't affect image quality, as compared to a fixed focus cam.
Instead, varifocal lets you "dial in" the FOV you need. Typically, after you identify the optimal cam mounting location.
That fence dictates the cam must be located high, to get the downward angle to catch the plate. The high mounted cam is a less-than-ideal location, however.

I would consider a small box on the fence that is inconspicuous, mounted about 4ft off of the ground, so that the camera is protected.

Coworkerbob, that's good advice (above) from bababouy. Consider mounting the box on the inside of the fence. Then just cut a round hole in your fence for the camera. The hole will have to be large, to eliminate reflections from the cams IR LEDs. You can make the hole in the fence smaller and more discrete if you turn off the cam's IR and use auxiliary IR illumination, located away from the cam. Eg: on the high spot where the cams are located now.

Would a 12mm lens have captured better plates?

Short answer, YES!
Read up on "Pixels Per Foot". A higher PPF gives sharper images. Visit the IPVM Camera Calculator site. Enter you address, it will use Google Maps to approximate the PPF from the cam to the subject, for a given lens size.

I suspect you cropped the 3 of the 4 images you provided.
1) only 1 image had the time and date stamp. (the date is 12/1/2000. The same date flashing on your VCR? Just good natured ribbing, lol)
2) I kinda doubt you have 4 cams aimed at nearly identical areas of interest.

LPR at night is a challenge. And not an easy objective to achieve. There's many threads here on the subject.

Your neighbors were burglarized. And your neighbors appreciate your help, and your security cams. Here's an idea:
Mount a cam on their property, recording to your NVR.
- For their privacy, mount it looking away from their house/windows.
- If next door neighbors, running cable is simple.
- if across the street neighbors, a point-to-point wireless link is better than relying on Wifi. Lots of threads here explain how to connect point-to-point wirelessly (better than WiFi, which sucks for security cams)

Your NVR probably has inputs for "external alarms". Consider using them, if only to get the "alarm event" marked on the video playback timeline. External alarms could be a switch on your front gate, a light tripwire (as with front doors of retail stores), or a PIR+Radar sensor. These are more robust, with fewer false alarms, than MD or IVS. (your costco units may not support IVS?)

Lastly, a Camera System is a lousy substitute for an Alarm System.
- When an Alarm sounds, it's a deterrent. The thieves won't linger.
- A Camera System might be a deterrent, if the cams are visible to the burglars. And if they care. If they have hoodies, they'll cover their face.
- To use a favorite quote from @looney2ns, cameras can give a false sense of security. After the thieves leave, the homeowners then learns the painful lesson:
"The Camera showed 'WHAT' happened, but not 'Who Did it!"

Best wishes to you for helping your neighbors, and making yourself more secure.

Fastb
PS: don't forget to "like" bababouy and tangent for their help!

 

[tangent]

Right on top of the fence would work too, a junction box and camera perched right on top of the 4x4 post. The OpenALPR docs recommend both the horizontal and vertical angles be less than 40 degrees. They actually recommend the camera be elevated some to avoid headlight glare.

 

[coworkerbob]

those are some great ideas. I was dreaming up a bird house with a hidden camera inside mounted on a 4x4 inside the fence but the holes in the fence works well too. I might go the varifocal "pixels per foot" route first to see i can get a better shot before investing in a dedicated lpr. The dedicated would require another wire pull or a poe switch in the attic.