EOS SL1 auto focus doesn't work. Seems to happen on hot days

[Bankesmom1]

My Rebel SL1 with a Tamron telephoto lens won't auto focus on warm days.  It will sometimes work at close focus, but when zooming in, it won't auto focus. Does anyone have an answer to this.  Same thing happened last year, but my local camera shop could give me no answers.  It was the shop where I purchased the camera, and I was disappointed with their response.  The weather has warmed up, I wanted to take pictures at a grandson's baseball game and no autofocus.  Frustrating.

[Bankesmom1]

Gotcha

Thanks

[Bankesmom1]

Thanks.  And I put it in manual after it took that out of focus shot.  

[Bankesmom1]

This seems to be a common statement as to what the problem might be.  Thank you.

[Bankesmom1]

I don't expect the lens to automatically focus when I have it in manual mode.  I switched the lens to manual focus, so that I could catch the action.  I had to focus it myself.  I've never expected it to focus automatically while in manual mode.  

[Anonymous]

"I switched the lens to manual focus, so that I could catch the action.  I had to focus it myself.  I've never expected it to focus automatically while in manual mode."

Since you focused it yourself in manual focus mode, why were they so out of focus? Were you unable to focus the lens manually?

[Bankesmom1]

Would that be the case even when I give it plenty of time to focus, and when I push the shutter release down halfway, nothing changes?

[Anonymous]

Try using P (Program) mode shooting and select the center point for the focus point and one shot focusing mode. See if that improves the focusing with that lens.

[Bankesmom1]

I will give that a try.  However it defeats the purpose of getting good action shots.  Thank you.  And it has worked for years!!!!!!  This is a recent problem.

[Anonymous]

Well, then it sounds like a problem with the Tamron lens. Could the Manual/Auto focus switch on the lens be dirty? You could try repeatedly moving the switch between M and A to clean up the contacts of the switch.

[deebatman316]

The metadata reports MF or AI Servo. It could possibly be the AF/ MF switch on the lens. Also AI Servo has NO focus lock. So the camera will fire the shutter regardless of if the subject is in focus or not.