You want to focus more on details and less on a wide angle of view? Then you should use the 16mm lens. By simple changing the lens you will get an angle of view of about 25°.
The IN-9008 Full HD and IN-9408 2K+ IP camera comes with a build in 4,3mm wide angle lens that offers a 90° viewing angle.
With the 16mm lens you will see an angle of 25°, so you actually see much less then with the original lens, but on the other hand you will see much more details inside the image.
Recommended distance: minimum of 15-30m to the target