AF points and Metering

Are the AF points (red squares) purely for focusing or does the camera meter on those points too?

I am asking in relation to taking two expsures and blending in PS.

EG:

I want to take two shots of a landscape. One metered for the highlights and one for the shadows. Do i just use bracketing or do i set the the red AF point near a highlight and shoot and then one on a shadow and shoot.

Thanks

Depends on the metering mode. IIRC, in Evaluative, it weights the focussing point more heavily. What I'd do for your situation is use partial or area metering and bracket or EC without shifting the focus or aim.

Only evaluative metering uses the active AF points, and in the 1D Mark II you can link spot metering to the manually selected active AF point.

In addition in Flash Metering, ETTL biases the active AF points and ETTLII does not.

Regards,
Scott