Auto-Tracking Cam's vs. Fixed

[StanleyEs]

I emailed this enquiry to info@use-ip.co.uk but no response as yet, thought i'd try on the forum.
I need CCTV covering the two ends and one side of an industrial building. The site is shown below:

We really would like a decent chance of reading number plates from the footage which I am aware is very difficult. You can see the site is surrounded on two sides by fields and there is no fence. Often intruders will just drive on to the site over the fields, so we cannot simply monitor the entrance with a high res camera. My first thought was to use 2 auto-tracking camera’s corner mounted so each camera would cover one end and half way up the building side, (Corners A and B on the jpeg)

Having looked at your range of PTZ cameras that include auto-tracking I notice their resolutions are pretty low compared with static camera’s (e.g. Axis Q6032-E is only 704x576). This concerns me because when I tested the Vivotek IP7161 camera it was clear that resolution is King when trying to capture number plates, especially if you don’t have a narrow entrance/exit to zoom in to. Since the PTZ cameras are lower res you would be relying on the auto-tracking to zoom in sufficiently to provide a the required level of detail. Another issue is that due to the possibility of intruders entering from any 3 sides the PTZ camera may not be pointing the right way at the moment they arrive. You would be relying on the pre-configure “tour” feature to eventually land on a scene containing the intruders and then for auto-tracking to take over. This could mean you have lost your best chance of capturing the number plate.

This makes me think if I would have a more reliable system if I use a number of fixed camera’s with as high resolution as possible. With this method I could more or less predict the zones where a plate will be legible and so position those zones to best effect. For example if I used 6 of your Sanyo VCC-HD2300P camera’s, 3 on A & 3 on B, then I could get decent coverage and have 6 zones where plates will be legible without relying on the camera’s auto-tracking feature.

In terms of cost the PTZ cameras are so much more expensive than fixed cam’s there doesn’t appear to be much difference.

Do you think I’m talking sense or are the auto-tracking camera’s so good they could be relied upon to find the intruder, zoom and capture the number plate? As I haven’t had one to play with it’s tricky for me to know how good they really are. I have seen footage on YouTube and could see the camera’s definitely tracked but wasn’t convinced I’d ever get a number plate from it.

Any advice offered is appreciated, regards Guy

 

[Phil]

Hello Guy,

Firstly, apologies for the delay in responding, it's been so busy here ...

Forget tracking PTZs, they simply will not track as you hope.

Number plate capture can be difficult at the best of times. Ideally, as you know, you would concentrate on a bottleneck area of minimal width (typically the site's main entrance/exit) and deploy as much resolution as you can afford to that limited width.

You also have the issues of light & movement; only specialist number plate cameras using reflected infra-red will reliably capture number plates from vehicles approaching with their headlamps on. Fast shutter speeds are necessary to capture clear stills of moving vehicles. Fast shutters only allow limited light to enter the camera. So you have an adjustment compromise between keeping the shutter speed sufficient to permit enough light to render a useful image in most conditions, and having a clear still with no motion blur.

In the scenario you describe, what you propose with an array of high-res IP cameras is probably the best compromise that you can deliver.

The Sanyo 4MP IP cameras offer lots of resolution at a good price, but perhaps not the best low-light performance. I'd recommend installing additional lighting around the buildings, preferably white light (not yellow SON lamps).

Be careful to set realistic expectations, don't promise to capture all number plates ...

You could consider PTZ cameras with PIR detectors and the use of a professional remote Alarm Receiving Centre to react to detections and control the PTZs remotely to capture useful evidence, and even to warn-off intruders. Bear in mind that most ARCs are not keen on 'open' sites - too many false activations - and many will wish to charge for their wasted time.

Have they considered a fence?

 

[StanleyEs]

Thanks Phil, very informative stuff.

My first response to the customer was suggesting they put up a fence. They said they had been quoted 15K which put them off. They may reconsider once i tell them the cost of multiple camera's and the fact number plates will in no way be guaranteed. There is external lighting but i think they are SON unfortunately.

thanks again, hopefully i will be in touch soon to place an order.

regards Guy