2,8mm vs 4mm camera?

[koaly]

Hello guys,
I am new here and also new in CCTV world. So, I am learning everyday. I want to install CCTV in a new house and I am challenged now by selecting proper Focal length for Hikvision DS-2CD2087G2-LU cameras.
As I did not have any experience and software, I tried to fit available cameras to places, where I intend them to be mounted.
As the area is not large I started with 2,8mm and then after a month tried to fit 4mm lens camera.
I like the picture from 4mm more, because then I do not need to hide private areas of my neighbors, but what I learned afterwards, the Depth of Focus for 4mm starts from 7m, whic is out of my area and starts on the side-road. 2,8mm Depth of Focus is from 4,5m, which sounds much better.
Please take a look on the attached liveview screenshots.
Could you advise, how crucial this parameter in real life is? Both pictures look clear and in-focus. May be it will look different at night?

Shall I set 2,8mm or 4mm camera in this position?
Thanks in advance

 

[Dan]

Hi @koaly

We would probably recommend the 4mm because it covers the specific area you want (no wasted FoV) and the narrower FoV means you get more pixels per meter, giving you greater detail for identifying faces.

If you are trying to decide between the 2.8mm and 4mm, we recommend doing some thorough testing. Record the cameras, review the footage of both day and night, perform walk tests day and night to see how each handles people/faces, and just check the footage/performance as regularly as possible to see how each performs in different conditions.

 

[koaly]

Many thanks!
That means - field tests are at the end of the day better than theory. Right?
I will try them both as they are equal on mounting.