5dmkIII w 1.4 tele and 70-200 f2.8 IS focus issue and speed?

I just got my 5d mark III and loving it. But I am having some issues that I am not sure if user error, or issue with my camera.

I was shooting my daughters soccer match the other day my settings were this
Manual
1000 f4 -8 (playing around with settings)
AI-Servo
High speed shutter capture
Focus Mode is on the sport one that says recommended for sports. 4th Icon down on the focus screen I think, I don't have camera on me at the moment to look.
I have the focus on auto find subject.
70-200 f2.8 IS (couple year old lens)
canon 1.4 teleconverter (couple years old lens also)


Things I notice:
It keeps hunting and searching to lock focus. When I first test this it was perfect. Now it locks on and then looses and starts hunting around screen. I am not sure if the 1.4 teleconverter is causing the issue. I don't think this was an issue when I was not using it for testing when I first got camera. This an issue?

When I have it in high speed shutter, I think it is only taking 2-3 pics per second. When I change camera to AI-Focus then the shutter fires full speed. I think this is tying back to the focus issue from above.

Can the 1.4 teleconverter cause an issue?

I use a 70-200 f/4L IS with 1.4x frequently on 6D and 1DIII. I notice no focus issues at all. Speed and accuracy is fine on both setups. I'm not sure how relevant that is to a 5D3, though.

bphillips330 wrote in post #18008781
I just got my 5d mark III and loving it. But I am having some issues that I am not sure if user error, or issue with my camera.

I was shooting my daughters soccer match the other day my settings were this
Manual
1000 f4 -8 (playing around with settings)
AI-Servo
High speed shutter capture
Focus Mode is on the sport one that says recommended for sports. 4th Icon down on the focus screen I think, I don't have camera on me at the moment to look.
I have the focus on auto find subject.
70-200 f2.8 IS (couple year old lens)
canon 1.4 teleconverter (couple years old lens also)


Things I notice:
It keeps hunting and searching to lock focus. When I first test this it was perfect. Now it locks on and then looses and starts hunting around screen. I am not sure if the 1.4 teleconverter is causing the issue. I don't think this was an issue when I was not using it for testing when I first got camera. This an issue?

When I have it in high speed shutter, I think it is only taking 2-3 pics per second. When I change camera to AI-Focus then the shutter fires full speed. I think this is tying back to the focus issue from above.

Can the 1.4 teleconverter cause an issue?

Your all points AF will typically lock on closest subject. I suggest you at least start with center point if using All points.

I've used the 2X tele with the 70-200 2.8 on my 6D and it causes a noticeable slow down in focus. No hunting, just slow.

So......I got the 100-400 II.......took care of the slow focus issue.

Make sure you are in 'case 1' AF mode and not on some super-sensitive mode. Also I'm not sure about 'auto find subject'. I only use a single point (with expansion). I never let the camera decide what to focus on.

bphillips330 wrote in post #18008781
...Can the 1.4 teleconverter cause an issue?

Absolutely, yes. Test without the T-Con and see for yourself if that solves the problem.

The 1.4XII on the original 70-200mm f/2.L IS should work well in decent lighting conditions, however the T-Con will always slow focus to some extent.