6D autofocus anomaly

[wsmith96]

I was out today shooting birds in the front yard using a 6D and a 100-400MkII. I had the camera set to the center autofocus point. When aiming the center AF point at a branch I set up for the birds to perch on, I couldn't get a consistent lock when the AF point was directly on the branch. Now this branch isn't very wide - say about 1/2 - 3/4" but if I moved the camera to where the branch was centered between the center AF point in the view finder and the circle that surrounds that AF point, at about 11 o'clock, I could focus every time. I'm about 5 feet from the branch.

I'm pretty sure this requires Canon to investigate, but I wanted to ask the group if there could be something I'm doing wrong, or other things to try. I'm shooting song birds (cardinals, blue jays, titmouse), so they aren't big to begin with and I depend on that center AF point. I also feel that the camera hunts more with the 100-400, where as my 60D doesn't appear to have a problem with it. I can't say I've noticed this behavior before, but then again, I just now have a lens capable of 400mm.

Any ideas?

 

[Corydoras]

Sound like a misalignment in the focus system. The focus system might not be in the same line with the markings on the focus screen.

 

[Viggo]

If you take a shot of anything, and pay careful attention to where you put the point, then activate "show AF point" in Play mode, you can see if the red square there matches your VF or not.

 

[Corydoras]

If you take a shot of anything, and pay careful attention to where you put the point, then activate "show AF point" in Play mode, you can see if the red square there matches your VF or not.

This feature most likely assumes that the actual focus point is where it should be, so it might not provide any useful data.

 

[Viggo]

If you take a shot of anything, and pay careful attention to where you put the point, then activate "show AF point" in Play mode, you can see if the red square there matches your VF or not.

This feature most likely assumes that the actual focus point is where it should be, so it might not provide any useful data.

No, it shows you if the ACTUAL focusing point is where it is in the VF. The difference between where you see the point being, and where it actually is. Did this on my 1dx as it was a problem on a few of them. If it's not in the same place, there is a misalignment.

 

[Corydoras]

If you take a shot of anything, and pay careful attention to where you put the point, then activate "show AF point" in Play mode, you can see if the red square there matches your VF or not.

This feature most likely assumes that the actual focus point is where it should be, so it might not provide any useful data.

No, it shows you if the ACTUAL focusing point is where it is in the VF. The difference between where you see the point being, and where it actually is. Did this on my 1dx as it was a problem on a few of them. If it's not in the same place, there is a misalignment.

That is new information for me! Previosly I thougt that it is only a simple overlay.

 

[Loswr]

If you take a shot of anything, and pay careful attention to where you put the point, then activate "show AF point" in Play mode, you can see if the red square there matches your VF or not.

This feature most likely assumes that the actual focus point is where it should be, so it might not provide any useful data.

No, it shows you if the ACTUAL focusing point is where it is in the VF. The difference between where you see the point being, and where it actually is. Did this on my 1dx as it was a problem on a few of them. If it's not in the same place, there is a misalignment.

Exactly. Ideally, set up on a tripod and locate the AF point on a unique, identifiable feature. If the red AF marker on the LCD playback is not over that feature, there is a misalignment and Canon needs to fix it.

 

[wsmith96]

Thanks for the info and sorry for stepping away - work has called me to Austin. I'll check this out when I get back home.

Thanks again!