Infrared is invisible. You cannot purchase visible IR lol. The camera needs a special filter to be able to see that light.
Now there are two types of IR sold are two wavelengths. 850nm is what most cameras see. If you look directly at the camera straight on, you may see two little red glow eyes LOL. 940nm you do not see the red glow when looking straight at the camera, but it's range is not as great, if the camera will even see it. But again, you will not see the IR light walking around and someone on the sidewalk won't know they are being blasted by IR light.
In most instances, the IR that is on the camera is sufficient. Some will use external IR, but those are unique situations or you have a situation where bugs are triggering the camera all night as they pass by the IR.
All of mine using IR are using the on-cam without any external IR.
I'd suggest you get a camera that has IR capability and then test it and see which works better. And it may be seasonal as well. I have one camera that I will change from color at night to IR based on the season.
Now there are two types of IR sold are two wavelengths. 850nm is what most cameras see. If you look directly at the camera straight on, you may see two little red glow eyes LOL. 940nm you do not see the red glow when looking straight at the camera, but it's range is not as great, if the camera will even see it. But again, you will not see the IR light walking around and someone on the sidewalk won't know they are being blasted by IR light.
In most instances, the IR that is on the camera is sufficient. Some will use external IR, but those are unique situations or you have a situation where bugs are triggering the camera all night as they pass by the IR.
All of mine using IR are using the on-cam without any external IR.
I'd suggest you get a camera that has IR capability and then test it and see which works better. And it may be seasonal as well. I have one camera that I will change from color at night to IR based on the season.