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]

No.  I take pictures at basketball games, and football games too.  And it's never been an issue in those circumstances.  Any other ideas for me?  Thanks for the input.

[Bankesmom1]

Thanks for the philosophy lesson, but yes, I have tried this lens in both hot, cold and warm.  Baseball, football, and basketball.  Hence the different temperatures and my deduction that possibly the hot temperature could be the variable that makes this happen.

I do use a Canon battery, the one that came with the camera.  I, too, have wondered if it might be the battery. Would you suggest buying a new battery then? In some of the reading I've done, I've seen some comments are the settings for exposures.  All good points, and thank you so much for your assistance. 

[ebiggs1]

For sure. Cause and effect, drawing incorrect conclusions.

[Bankesmom1]

Ouch

[ebiggs1]

My intention was to make sure you don't associate some cause as the reason for the failure and it not being the correct one. I will bet you "warm" is not the only component going on. It may very well be the reason but I only want to make sure you evaluate all possibilities.

You said later that the lens works using it for football and basketball? Doesn't that almost clear the lens form being faulty?

Another statement I am going to make and please don't think it being rude but almost all focus misses are user caused and not camera/lens. So I am going to recommend you reset your Rebel SL1 back to factory default settings. Also make sure the lens is set to AF. Set your Rebel to P mode. Set ISO to 200 and daylight WB. Very important set the AF mode to One Shot not Ai-servo, never, never use Ai-servo. Large jpeg file. Now go outside on a nice sunny day and shoot some random shots. All kinds of different stuff like trees, buildings, people and pets, etc. Random shoots. Now u/l to your computer and check what you got. If all is well and good there is nothing wrong with your camera/lens combo. If it fails this test one or the other is faulty. This is simple, easy to do and will let you know where the problem lies.

I can't stress enough you do this test. Plus ignore all the other suggestions until you do this test. We have to have a base line to start out with and it is impossible to solve the issue until we do.

How to reset the Rebel, Menu>Tools> Clear all settings and Clear all custom settings. Consult your manual if need be.

[Bankesmom1]

I am going to put everything back to factory default and go outside now and shoot some shots.  I'm willing to try anything.  I'll do everything that you suggested.  We have another baseball game tonight too, so I'll try shooting shots using what you have suggested.  Stay tuned.  Thanks for the advice.  

So, I'm back in and have downloaded the pictures to the computer and they look great.  Even the trash truck traveling at 60 MPH 75 yards away from the house looks great.  It's a very smoky day here in southeastern Ohio.  Major air quality alert going on here from the Canadian forest fires.  We can see and smell the smoke in the air.  I'm pleased.  

We have 2 baseball games tonight.  SHould I leave it in the same settings for those games?

[Bankesmom1]

[ebiggs1]

That's great but the settings I advised were just for the test to confirm the camera/lens is OK.

Settings for a sporting even will be somewhat different. You said you used Sport mode? Sport mode essentially turns your camera/lens into a point and shoot (P&S). Sometimes that works and sometimes it doesn't. I would refrain from using any full auto mode like Sports mode.

Not knowing the conditions of your game tonight not me nor anyone here can give you good settings. So, can you explain what you will be shooting tonight. One advice is stop using Ai-servo or any similar focus mode. Use One shot and preferably just the center focus point. When you do this make very sure you put that center focus point exactly where you want to focus.

[Bankesmom1]

In answer to your questioning my reasoning for blaming the heat, the heat was the only variable going on.  Same camera, same lens, same settings.  But if it is a hot summer day, invariably, the lens will eventually stop auto focusing.  That's why I deduced that the heat was the factor.  I tried to upload more photos but it tells me the files are too large. 

[ebiggs1]

Another tip if you have not already d/l the DPP4 photo editor from Canon do it. It is free and it will open up a whole new world with your photos. Using it you can downsize your photos so you can display them here. Plus you can do simple to difficult edits. 

Get back with the conditions of your baseball game tonight.