Subscriber Discussion

WDR For LPR Or Not?

I need to decide on whether I should opt for a camera with WDR or without to recognize number plates at the security gate. This is an open area where the camera is at least 30 meters away from the gate and camera has a varifocal lens or 5-100mm.

Should I opt for WDR or would it be okay without it?

Cameras with true WDR use multiple exposures, typically including one that is relatively short. During the day, this is typically not a problem, as there is a lot of light. However, at night, this frequently results in worse low light performance (and with some manufacturers blurring). This is why many manufacturers automatically turn off WDR at night.

At the very least, you are going to want to turn WDR offf at night.

Probably the biggest variable is how wide a FoV do you want to cover. You should be fine using a 5 - 100mm lens for an object 30 meters away, but is the FoV narrow (i.e., just one lane) or wide (4 lanes and the adjacent building, etc.).

Thanks John

It is just one lane which is 6ft wide.

So I rather go for the non-WDR model which would save me alot of bucks :)

With one lane, you are unlikely to have great variances of light (outside, of course, headlights at night).

As for saving money, be careful here. You should strong consider using a specialized LPC camera that has integrated pulsed IR, appropriately configured / tuned camera, etc.

Some background information can be found in our License Plate Capture Shootout and Discussion on LPC Night Time challenges.

Can you suggest some models for LPC?

I am considering Sony CH120 + IR Illuminator

I wouldn't think WDR would be a good idea for LPR in any circumstances. In my limited work with capturing plates, it's generally the case that you want the highest contrast possible to help the characters stand out from the background, whereas WDR effectively reduces the overall contrast (in addition to John's other caveats). A "masking" technology (CNB's Blue-i comes to mind) that electronically "blots out" bright areas like headlights MIGHT be more suitable...

John's right, there are cameras out there designed specifically for LPR; they're spendy, but if it's for something critical, it's probably worth it.

There's a company called GPI360 that makes a WDR LPR camera that just gives you the license plate. It has a global shutter and uses IR illumination, so you don't have to worry about motion blur.

Thanks All

How much does FLPR-2650IP cost? And who sells it?

There is a "contact us" page on their web site with a phone number.

I don't know if they sell through a distributor or another channel.

I have got the FLPR2650IP from Gpi360 and have installed it 30 meters away from the security gate. Other than technical specifications, the package did not include instructions on how to configure and install the camera.

From live view, the picture is black and cannot see anything other than near objects in BW. How can I adjust the focal length and focus with very limited view

Also ONVIF does not seem to work

Its been difficult dealing with GPI360

How has their phone support been? If you can't get a straight answer from them quickly, my gut feel would be to return it. I have no idea who that company is.

The camera is a ambient light rejection camera. I didnt quite understand what I bought until I saw the liveview.

Below is a snapshot taken late afternoon. Plenty of light but all I see is the elbow of guy fixing it.

Many 'true' LPC/LPR cameras do that so they can optimize/isolate for the plate. The tradeoff is losing the rest of the scene.