Cop Dvr And Day/night Cam Vs Ir

[zs123]

Hi everyone,

I read a good few posts on here a registered today.

Basically i m looking for a home cctv system with a max of 4 cameras. Im getting a second hand Cop VT MJPEG DVR as for now its all i can afford.

I was going to get a sony ccd IR camera but i have read on here that a 'true' day/night camera is better if the are is lit (i have 150w pir on driveway) as it doesnt attract spiders etc. But what are these true day night cameras and whats the difference, can you get one for under 150 pounds?

Lastly i wish to monitor an area approx 15 metres long by 8 metres wide, for this i was thinking of a 6mm lense is this about right? I would like facial recognition at 15 metres so was going to install a second camera with an 8mm lense will this be sufficient?

thanks for any advice you can give, apologies if this is boring newbie stuff but it seems to be a minefield !

[sjonley]

Hi

The cop dvr is adequate for your purposes but think about this. you are buying a second hand dvr. I'll be surprised if it has any warranty. The vt could be as old as 3 years old or it could be within that time frame.

Regarding the cameras. A true day night camera means it has a moving IR cut filter. This means that during the day the cut filter is covering the image sensor stopping the ambient ir that is part of the daylight spectrum. As the light level drops, internal sensors within the camera move the ir cut filter out of the way and replace it with a piece of glass with the same optical characteristics as the cut filter. This now allows ir lighting to fall on the sensor enabling the camera to effectively "to see in the dark." Cameras of this nature tend to be bullet or can style cameras with inbuilt ir illuminators in the form of led's aurrounding the camera lens. I would always half the quoted distance of the ir illumination for a useable image ie. if the manufacturer says ir illumination upto 20m, this normally relates to ideal situations. In reality, 10m max.

CCD sensors that are usually associated with true day/night switching tend to be Sony Ex-view or Sony Ex-wave. These are the latest ccd technologies from Sony and give the best response in low light conditions. This does not mean that the cameras are made by Sony. Sony is only quoted due to the sensor used. I will be very surprised if you can get a Sony Ex-view CCD, ir moving filter camera for less than

[zs123]

hi stuart, thanks for taking the time to reply thats really informative i will have a think about the points you raise. i cant really afford more than 170 for the dvr so im limited to second hand i think as a i would like it to be networkable.