In theory the higher the resolution the better your CCTV, more pixels means more detail. Well not necessaritly....
At the moment there are lots of systems on the market claiming ultra high resolution right up to 4K. The problem is in most cases the cameras are wide angle meaning pixels spread apart quickly as you move away from the lens. It's like trying to heat your house with the doors and windows wide open, you will never win. What does happen is you generate a massive amount of data which quickly fills up the DVR's hard drive and you have very short storage times.
HD 1080P gives a great image when coupled with the right camera. To double the quality of HD 1080P you actually need to increase to 8 Megapixels as you are increasing on 2 axis, the horizontal and the vertical. You get the square root of the increase in pixels so 3 or 4 MP won't actually improve the image much but it will halve your storage time.
It's the same old story, people who don't really understand CCTV jumping on a bandwagon and using impact phrases to try and sell their products.
Throwing pixels at your CCTV system just fills up the Hard drive faster. 21 days rolling footage in HD1080P suddently becomes a mere 2.6 days rolling footage in 4K. Instead of fitting a 3TB hard drive you need to fit a 24TB one!
CCTV image quality all comes down to pixel density, how many pixels hit the target and it's measured in pixels per metre - PPM. The best way of improving images is to use cameras with an optical zoom that can be zoomed in on the target area during installation.
A HD 1080P camera set properly so that it films 8 metres across the screen at a distance of 12 metres would have an angle of view just over 35º and give a pixel density of 240 PPM
A 4K wide angle 90º angle of view camera would only give a pixel density of 160 PPM at the same 12 metre distance
Rather that waste money on 4k CCTV spend a bit of time thinking about where you need to record detail then use the correct cameras rather than generic wide angle ones. We are always happy to chat over the phone whilst looking at your property online and come up with a solution which gives excellent results. Call us on 01895 233311