Wide Angled Dome Cameras

[The Max]

One of my clients has asked me to Install a dome camera with wide angled lens for the purpose of looking out at his rear car park, the thing is he would like to see the registration plates of any cars coming and going, day or night. can this be achieved? Any info would be appreciated.

Max

[The Max]

It isn't a dome but Eneo do a single camera that can be setup to use 3 inputs on a DVR - say wide angle plus zoom image of number plate and zoom image of driver.

I'm not sure of its low light capability but it is aimed at car park entrances to display vehicle, driver and number plate.

Enterprise Security will have details if you need them.

Any idea of how well it works at night time?

[Alpat Systems]

One of my clients has asked me to Install a dome camera with wide angled lens for the purpose of looking out at his rear car park, the thing is he would like to see the registration plates of any cars coming and going, day or night. can this be achieved? Any info would be appreciated.

Max

Hi Max,

How wide is the area to be covered, Is there just one entrance/exit, Is there currently any lighting within the area, what's the budget?

[The Max]

Hi Max,

How wide is the area to be covered, Is there just one entrance/exit, Is there currently any lighting within the area, what's the budget?

The area of the entrance point to be covered is roughly 20m x 15m and theirs only 1 entry/exit point. The lighting for this area is 1 street light at the entry point into his car park. He was hinting that price was not a problem as long as it was fit for the purpose.

Thanks

Max

[Alpat Systems]

The area of the entrance point to be covered is roughly 20m x 15m and theirs only 1 entry/exit point. The lighting for this area is 1 street light at the entry point into his car park. He was hinting that price was not a problem as long as it was fit for the purpose.

Thanks

Max

There's a few options to cover this:

If reading number plates is number one priority, I'd always suggest a number plate recognition system. You pretty much have guaranteed results then.

PTZ dome with PIR sensor. PTZ's home position could be "zoomed" out so covering entire area. PIR to be positioned across entrance area so once triggered PTZ would "zoom in" to cover entrance.

Use 2 static cams, one giving a general overview of area, second "zoomed" onto entrance.

You mentioned using a dome earlier, are you referring to a vandal dome?, or PTZ dome?. Is there any mounting points for the camera(s) or would a pole/tower be required. Ideally if you had a picture of the area, I'd have a better idea of the layout.

It isn't a dome but Eneo do a single camera that can be setup to use 3 inputs on a DVR - say wide angle plus zoom image of number plate and zoom image of driver.

I'm not sure of its low light capability but it is aimed at car park entrances to display vehicle, driver and number plate.

Enterprise Security will have details if you need them.

From memory, I think the Eneo cam does 0.001Lux in black & white.

[The Max]

My customer already has external domes (which i did not install) on the ouside of his building and he was looking for a dome with a wide angled lense which would not to look out of place, but the purpose was just to look at car registration plates. My concern was at night, the car headlights would interfere with the picture because the entrance to the car park was about 15m so therefore i could not pinpoint the camera to a exact point.

The Dome has to be mounted onto the side the building.

Regards

Max

[Alpat Systems]

My concern was at night, the car headlights would interfere with the picture because the entrance to the car park was about 15m so therefore i could not pinpoint the camera to a exact point.

The Dome has to be mounted onto the side the building.

Regards

Max

See what you mean now.......

Number plate recognition using a standard cam with wide angle lens is going to a problem.

Take for example motorway roadworks with average speed, speed camera's that record number plates. They tend to use 2 cams to cover a 3 lane motorway, as one cam cant capture enough detail.

Have a read of these links, there's some good info on there:

http://www.cctv-information.co.uk/constant3/anpr.html (Scroll down to this bit The Application of Infrared Illumination to ANPR & Cameras and Lenses)

http://www.licenseplaterecognition.com/

[The Max]

Many thanks for this Info

Regards

Max

[Doktor Jon]

The problem here The Max, is your client is laying down naive equipment requirements, without really understanding the technical limitations, which need to be addressed in order to achieve their operational objectives.

Achieving what is required should be fairly straightforward and not necessarily expensive, but if the client is going to dictate what they want you to use, they're certainly not doing you any favours.

Are you saying that the actual drive in / out is 15 metres in width, without any seperation of traffic flow? Can you locate a camera at perhaps 30 - 40 degrees off centre (preferably at some distance)? Is there any low level maintained lighting at night, or is that an option?

I personally wouldn't use a remote control camera for this application, but rather look at using fixed cameras which are properly optimised for the task in hand.

[Alpat Systems]

To capture a number plate succesfully you need to take the following into consideration:

Camera/Lens

Illumination available

Vehicle speed

Camera Position

Any decent camera will capture a number plate to some extent, especially if the vehicle is stationary

Long post bit

The size of a UK license plate on cars and commercial vehicles is approximately 510mm long x 110mm high. Motorcycles are different being approximately 255 x 200. However more significantly, the minimum height of the letters must be 79mm. The current UK font is Charles Wright, although there are some illegal formats seen. The size of the number plate and the actual characters will need to be of a certain size when seen by the camera for the OCR software to function. One line of thought is that the number plate should be 18% of the scene width; I prefer to consider the vertical height of the characters, which from previous research should be 3% minimum for a 400 line camera. This in fact equates very closely to the 18% screen width but is more logical when considering different shapes of number plates. (For instance when a car plate is 18% of the screen a motorcycle plate would only be 7 %.) Also note that motorcycles currently do not have to carry a front number plate, but this could change in the future.

This provides the first convenient way to calculate the lens angle. For 79mm high characters the scene height needs to be 2633mm. (79 being 3% of 2633). Therefore using a scene height of 2.633M and the known distance, it is a simple matter to calculate the lens angle and thus the focal length. At this stage the height of the camera has not been considered but would not make much difference for normal combinations of distance and camera heights. For an accurate and simple method use the LensCalc software and the top half of table below. The following table shows the lens angle for various distances and a scene height of 2.633M

Distance to target 5M 10 15 20 25 30 35 40 45 50

Lens angle 29.5