Josephpapa found a difference to the way the Nikon D3 camera autofocuses with the IR (infrared) beam from the external flash when compared to the Canon 1D Mark III camera.
With the Canon, all AF (autofocus) points are linked to the IR illumination assist beam, while on the D3, not all 51 points are linked to the IR beam from the Nikon SB-800 flash.
Because of this, it’s best to change the AF custom setting on the D3 to only use 11 points rather than all 51 so that’s it’s quicker to access the AF points that are linked.
After changing this camera setting, Josephpapa’s D3 now matches the Canon 1D3 in terms of initial focus lock speed, but with 40% greater accuracy.
The portion of the Nikon D3 manual that Josephpapa referred to in his post is probably the following (from page 195):
Tags: Nikon SB-800