The disappointing thing is that the built-in IR illuminators in the camera produce such a narrow beam. But this is typical of built-in IR illuminators.
I know it has to be a compromise, and that manufacturers want to be able to boast about a longer range for their illuminator. But since the camera designers knew the range of focal length adjustment that the camera would have, it would have been nice if they had used a wider beam
IR illuminator to better match the wide end of the lens' range.
Yes, you would lose some range at the long end, but a lot of us want to use the wider settings, and it's a shame to see the IR source be so narrow.
This is a reasonably priced camera, but a nice feature would be an adjustment for the beam widths of IR illuminators on varifocal cameras like this. That might add a lot to the prices, though.
Anyhow, I'm not as inclined to blame the user for the shortcomings of the camera. One should reasonably expect to be able to use the full range of adjustment of the camera's lens.
But since the camera is able to adjust to a view that is far wider than what the built-in illuminator can handle, it's important for him to at least understand why he is seeing what he's seeing.
I wonder if some adjustments of dynamic range settings or the like might help tame the "spotlight" effect to some degree. Or if a diffuser of some sort could be mounted over the IR illuminator(s) to spread the light somewhat.
But I also think that if it was me, I would look into an "on at dusk, off at dawn" white light or lights, or a separate, and wider-beam IR illuminator to better cover the desired area.
These cams do well with dim illumination. Some white light, and forcing the camera into color mode often gives very nice results.
The thing for the OP to realize is that if you want good exposure over a large area, you must provide even illumination of that entire area. Remember that using security cameras is just like any other photography. Lighting is critical because all cameras capture only a small "slice" of the dynamic range of brightness in a scene.
No camera can match the dynamic range of the illusions that our brains create using the information from our eyes as we look around over a scene.
Any camera/display system will capture and present us with just a small portion of the dynamic range in a typical scene. Anything too bright is "blown out", and all things brighter than the upper limit show up as the brightest white that the system can render.
And anything dimmer than the lower threshold renders as the blackest black that the system can render.
To deal with these limitations, photographers can either provide very even illumination of the entire scene, or simply elect to discard areas that are too bright or too dim. Sometimes that is actually desirable because we can concentrate the viewer's attention on the part of a photo we want to emphasize. Or purposely make the viewer struggle to see something, thus unconsciously making them concentrate on a subject, etc.
For security systems, we just want to be able to view a scene after the fact and make out the details necessary to see what happened and hopefully who done it!
So smooth, even illumination is our friend. But newer cameras like this also have WDR and other tricks to help even out the dynamic range of a scene. So make sure to use all of the adjustments available, and play with those settings.
