Visible LED on front of cam?

[Kentg]

OK I know IR is not visible to the eye from all I know but I have to ask. On my new Hik 4MP bullet 2CD2T42WD-I3 I noticed I can see a red led in the dark on the face of the cam. Forgive me if I have missed a little or a lot but why is there a visible external led on this?
I really don't want to advertise the presence of this cam like this in the dark.

 

[djangel]

Don't know all the technical info, but you will see the red lights at 850nm wavelength. I think at higher wavelengths the ir will not be noticeable, but you get less light. Something like that

 

[Michelin Man]

The IR leds are roughly in the 850nm range which is just at the end I believe of the visual range we can see. On the 2T series the leds are just covered by the darkened face unlike the other series where they are clearly visible.

At 940nm you won't be able to see anything.

If you seen a 2132 (dome) or a 2032 (bullet) you will think the slight glow from that 2T is nothing.

You would already have to be looking at the camera to see the red glow anyways.

EDIT: Supposedly our eyes have a non-linear response to light in about the IR wavelength range.