Canon T6i Auto focus works only on Live view but stops auto focusing on view finder

[diomedes]

I have a Canon T6i with a 75-300 zoom Canon Zoom lens. I have AI servo active. When I open the live view the camera automatically auto focuses as I move it around from object to object. But when I close the live view screen and look through the view finder nothing happens. I can press the back button focus button or half press the shutter button to reach focus but it does not try to focus on other objects after that initial focus.

[stevet1]

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@diomedes wrote:

But when I close the live view screen and look through the view finder nothing happens. I can press the back button focus button or half press the shutter button to reach focus but it does not try to focus on other objects after that initial focus.

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diomedes,

You have to continue holding down the back button focus or half-press the shutter button as you move around., If you only press the button once and let go, it will only focus once.

Steve Thomas

[diomedes]

Thanks ! I guess I was doing a half press intuitively  before I switched to back button focus, so I never noticed I was doing it. 

[stevet1]

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@diomedes wrote:

Thanks ! I guess I was doing a half press intuitively  before I switched to back button focus, so I never noticed I was doing it. 

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diomedes,

You can use that to your advantage too, especially if you are using back button focus.

You can center an object and focus on it, and then let go.

Then you can shift that object off to the side slightly, and then take your picture with the background all out of focus, but with your subject still in focus. It's called the focus and recompose technique.

Steve Thomas

[diomedes]

Nice! I will try this out tomorrow morning. I’m doing some bird photography