The AF-assist illuminator lights when lighting is poor. AFassist
illumination is only available when both of the
following conditions are met:
1. Single-servo autofocus is selected for focus mode (pg. 72).
2. Auto-area AF is chosen for AF-area mode (pg. 74), or
single-point or dynamic-area AF is chosen and the center
focus point is selected.

doesn't work in af-c
doesn't work with any other points other than the centre, even though thom hogan says there are more options. i tried what he said and it just doesn't work.

only the centre point or auto-area af work.

that said you could use a speedlite for af assist.

You can shut it off completely (which I did) for several reasons. First, it isn't very effective with the 24-70 lens with the hood on as it is about 90% blocked by the lens and hood. Second, when I am shooting in a dim room without a flash (so as not to annoy or distract others), what is the point of hitting your subject with a spotlight?

I never seem to have much issue with autofocus even in really dark areas as I often switch to a specific focus point and that one tends to have the most light in the image.

Thanks Niko, downloaded the manual and the issue is that the autofocus point is not set in the centre.

Doesn't much help for framing, but at least I don't have a problem, as you correctly surmised!

It also won't come on when you are using certain AF settings. Look over the manual to see if you do in fact have a problem but I'm guessing you don't.

Thanks Niko

It seems to not come on, even when it hasn't been used for a while, like for instance when I switch it on.

I have to download the manual.

The more you use the lamp consecutively the more it heats up. So it's designed to stop working to give itself some time to cool off. It's in the manual.

I was at a function the other night and was shooting in candlelight. I noticed, that the autofocus lamp was not consistent. Sometimes it was on and sometimes it was off.

When it was off, the camera still autofocused in some instances, although when very dark, it had trouble.

This leads me to believe that this feature is an automatic one which has a setting somewhere.

The lamp comes on when the camera is in self timer mode, but of course, not always when the shutter button is pressed.

Any advice, is it faulty, can it be set?