Help with AutoFocus on EOS Rebel T5i

[Loudaman]

I was gifted a Rebel T5i with several lenses. I've slowly been learning how to use it and have enjoyed taking some really nice photos .. until last week. My camera no longer autofocuses while using the viewfinder; I have to use the live screen to have it autofocus. This happens with all the lenses that came with it. I also purchased a Canon EF-S 18-135mm f/3.5-5.6 IS USM and that also won't autofocus while using viewfinder. I've tried cleaning the contacts on both the camera and lenses and still same problem. What are my options at this point? Do I need another camera body? Thank you for your thoughts and ideas.

[stevet1]

Loudaman,

What button are you using to autofocus when you are using the viewfinder?

Steve Thomas

[Loudaman]

I use the camera shutter button; pressed about halfway down.

[stevet1]

Loudaman,

Is it possible that you have inadvertently reassigned your focus to another button in your menu setup, like the  * button?

Steve Thomas

[Loudaman]

I tried my camera just now and I heard the lens trying to autofocus while using the viewfinder. It made a sound then stopped. I will look through my full menu completely to see what my current settings are; and I am going to reset the camera and check the autofocus. Thank you.

[deebatman316]

Can you manually focus the lens with the focus ring. This lens uses Nano USM which is focus by wire. The focus ring isn't physically connected to the focus elements in the lens. The focus ring has a digital encoder underneath of it. That tracks which way your turning the focus ring. Then sends commands to the camera so the AF motor can manually focus the lens. So you can turn the focus ring at anytime without any damage to lens. In order to use Full Time Manual focus you need to half press the shutter button (or the button configured for back button AF) and turn the focus ring. Make sure the camera is in One Shot AF mode. Full Time manual does NOT work with AI Servo.

[Loudaman]

I will do this before I reset. I will post result as soon as possible. Thanks again.

[jrhoffman75]

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@Loudaman wrote:

I was gifted a Rebel T5i with several lenses. I've slowly been learning how to use it have enjoyed taking some really nice photos .. until last week. My camera no longer autofocuses while using the viewfinder; I have to use the live screen to have it autofocus. This happens with all the lenses that came with it. I also purchased a Canon EF-S 18-135mm f/3.5-5.6 IS USM and that also won't autofocus while using viewfinder. I've tried cleaning the contacts on both the camera and lenses and still same problem. What are my options at this point? Do I need another camera body? Thank you for your thoughts and ideas.

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The inadvertent button reassignment described by stevet1 is a strong possibility. Since iut was inadvertent perhaps other changes were made. I suggest you reset camera settings as described in the manual to be sure.

[deebatman316]

I believe if back button AF is set up. It applies to both the viewfinder and live view. Very early cameras with live view don't support on image sensor AF. The AF-ON or * button must be used for AF. This drops the mirror and uses the dedicated viewfinder AF system. When AF is complete the mirror goes back into the lockup position.

[Loudaman]

I am definitely going to do this. I do remember re-setting it before but maybe not understanding exactly what I had done I could have changed something. I just turned on the camera and tried to autofocus through the viewfinder; the lens made a noise like it was working and stopped. I am going to take the lens off and going to reset the camera and check it again. Thank you.