D800 AF-S and AF-ON button, to get AF-Assist Lamp working

[alexthecheese]

Can someone please help me to get my D800 AF assist lamp working? An Exception told me it was because I am in AF-C mode, but I don't know how to switch it to AF-S, when using the AF-ON button to do the focussing. My shutter button does not do any focussing, just the AF-ON button.

It's driving me nuts, and I can't seem to understand anything on the internets about it.

 

[alexthecheese]

Oh for ****in' 'ell's sake, I've just found it haven't I. Click the AF button in on the side, rotate the dial. Why is it not in a menu?!

Yep, that's it. Why does it require that I sit down and make a post for my brain to give up the information? Works now.