5D classic CFn 17-1

Wow!
I was not impressed with my new to me 5Ds' AF acquisition speed at all for the first few times shooting until I changed Cfn 17 to 1. (Expanded). It makes such an amazing difference!

I was having little success in low light acquiring focus on center point and once I switch, bamm. It is very very noticeable.

Now why would you want that off?

To achieve focus on a specific subject such as a persons eye.

ahh i just looked at cfn 17-1 it is activating the 6 assisst points in af servo mode BUT i dont shoot in AF Servo mode.

binlerne wrote in post #8814931
To achieve focus on a specific subject such as a persons eye.

Why would you be shooting in servo for portraiture?

Some portrait subjects like todllers love not to sit and give you pose...They just run around.

mzondeki wrote in post #8815131
Some portrait subjects like todllers love not to sit and give you pose...They just run around.

Exactly. I shoot everything in Servo with AF expansion points, until the light gets too low and the lens starts hunting. The only real advantage to One Shot is that it allows more light to hit the AF sensor during the AF cycle.

Although, I have switched to One Shot for very close portraiture. As binlerne said, it helps achieve focus on a single eye. But, one could also do the same by switching off the expansion points.