7D Spot AF Point ?

I've been playing around with Spot AF and Single Point AF and really don't see a difference between the two. I tried focusing on a small branch in Single Point and moved closer until I was just able to obtain focus then switched to Spot AF but wasn't able to move any farther away.

Anyone else notice this ?

Spot AF and Single Point AF only changes the size of the AF sensor, but not its precision nor anything else.
Spot AF is supposed to be used in places where the bigger size of the Single Point would be an issue, like when trying to focus a bird between branches and leaves, so you can be sure the AF point will cover only the bird but not the branches or leaves...

Ok, So I just went outside and tried to focus on a tree trunk through a white metal fence with 1 1/2'" square holes. With the camera on a tripod I moved closer to the fence until I was just able to focus between the openings in Spot, then switched to Single Point and was still able to focus. Moved around a bit and went back and forth between modes and really didn't see a difference.

I first noticed this when I was trying to focus on a tweetie bird in the bushes and couldn't so I switched to Spot and still couldn't focus on him.

The manual says Spot covers a "very small area" but I just don't see it.

The camera's AF area is larger than the little squares you see on the focus screen. When you choose spot focus, you're reducing the AF area. The focus area still extends past the area of the square, but not as much.

For a good explanation check out the B&H video at the link below... Choose the one that says "EOS 7D, 1 of 3" and go to the 32 minute point.... (You'll probably want to watch them all). Each video is about 50 minutes.

http://www.video.bhpho​tovideo.com …dbee4f4d48db9a2​6a992d3ab2

yeah, i had the same experience...i also posted a thread here which showed that the actual area of focusing is not aligned with the markers in the VF. Tested both my 7d's and it was the same....

heres my post....would want some more people to test really.
https://photography-on-the.net/forum/showthre​ad.php?t=772805

That's a good idea, thank's. I'll do that test next chance I get.

saw something at dpreview that explains the af sensor layout....

http://forums.dpreview​.com …19&thread=33054​300&page=3

Jim_T wrote in post #10150945
The camera's AF area is larger than the little squares you see on the focus screen. When you choose spot focus, you're reducing the AF area. The focus area still extends past the area of the square, but not as much.

For a good explanation check out the B&H video at the link below... Choose the one that says "EOS 7D, 1 of 3" and go to the 32 minute point.... (You'll probably want to watch them all). Each video is about 50 minutes.

http://www.video.bhpho​tovideo.com …dbee4f4d48db9a2​6a992d3ab2

I was just going to refer the OP to this vid. Great minds think alike.

I've compared normal single point to spot AF and did find a difference.

In wich situation do you guys use normal or spot af ? Im always using spot af and dont see any reason of using normal single point.

When it gets a bit darker, or if the subject is lacking well defined contrasts, or if it's moving fast, for example. The normal or expanded single point is better than spot.