I had a hiccup yesterday when I finally had the opportunity to shoot a wild snowy owl. It was on a flagpole, and when it took off, I changed from single point AF to Auto Area. This was a simple thumb press, as I have both hooked up to different back-button-focus buttons. I've used this setup for years with no issues.
And then the lens started doing a strange, repetitive, short-distance focus racking. Perhaps three or four shifts in direction per second.
I had to follow the owl with single point. I was able to swap to my backup camera (a 5d4 with identical settings) and that one worked fine.
After the owl incident, I switched lenses on the questionable camera, and it did the same focus racking thing. I did find I could get auto area AF to work on very high contrast subjects. But not with lower contrast subjects, such as a snowy owl against the sky, or the line of a room corner leading up to the ceiling. My backup camera did these things fine.
I first figured I just have some odd setting switched on, but I literally went through the entire menu system, and there isn't anything set differently between cameras.
Could it be that there's a foreign object on the focus sensor or something? Just curious if this sounds like an obvious case of something. Thanks. -tig
And then the lens started doing a strange, repetitive, short-distance focus racking. Perhaps three or four shifts in direction per second.
I had to follow the owl with single point. I was able to swap to my backup camera (a 5d4 with identical settings) and that one worked fine.
After the owl incident, I switched lenses on the questionable camera, and it did the same focus racking thing. I did find I could get auto area AF to work on very high contrast subjects. But not with lower contrast subjects, such as a snowy owl against the sky, or the line of a room corner leading up to the ceiling. My backup camera did these things fine.
I first figured I just have some odd setting switched on, but I literally went through the entire menu system, and there isn't anything set differently between cameras.
Could it be that there's a foreign object on the focus sensor or something? Just curious if this sounds like an obvious case of something. Thanks. -tig