18-55mm lens has trouble focusing, but only sometimes

[ElleMo]

I’ve searched through posts but haven’t been able to find anything that fits my exact issue.

My lens for my CANON EOS REBEL T41 18-55mm lens has focusing issues sometimes but not others.  I have it on  A+ setting with autofocus &shake reduction on.  Issues seem to happen only with photos of people.  Landscape shots seem to be ok and even closeups of things. For example, photos of cherry trees look great as well as the close ups of the cherries but a group of people have somewhat blurry faces. But not always. Sometimes the people look ok too. And it happens on all different kinds of lighting.   I started noticing it a few months ago, but most of those pictures were inside so I thought perhaps it was poor lighting. but the more recent pictures were outside on a nice weather days.  

  I have had Canons Rebels for 11 years (this camera & lens are 4 years old) and am not doing anything different.

I have seen  posts about lens no focusing, but nothing about a lens that sometimes focuses, so I am not sure if this would be considered the same issue.  Any suggestions on how to continue would be helpful.

ETA:  It's not always a group of people.  It happens with photos of 1 or 2 people as well. 

I am not interested in changing ISO and using manual settings.  

I've been using auto settings for years with no issue until recently and would like to continue doing what I am doing.

I need to know if there is anything I can do to fix the issue and/or how to figure out if it is the camera or the lens so I can decide if I want to pay to get it fixed.

[Anonymous]

If some of the people in a group photo are in focus, but others are not, then you need to use AV mode and set the aperture to a higher f-stop number (smaller lens opening) to have greater depth of field to keep everyone in focus.

[ElleMo]

Why after 4 years would I suddenly need to change what I am doing?  I had great photos of people until recently.

I am not interested in changing ISO and using manual settings.  

I've been using auto settings for years with no issues.  Now I am having issues.  I need to know if there is anything I can do to fix it and/or how to figure out if it is the camera or the lens so I can decide if I want to fix it. 

I also edited my original comment to say: issues have happened with photos of just 1 or 2 people as well.

[ebiggs1]

ElleMo,

If you are not willing to do this, then we can not help you.   You need to determine if there is a problem with the camera first off.

"Here is what you should do.  First reset the Rebel to factry defaults.  Menus under tools clear all settings and clear all custom settings. Now set it to P mode ...

Go outside on a nice sunny day with the ISO set to 200 (not auto ISO, ...). Set WB to daylight.

Now find a nice contrasty shot and try a few. Something with vertical lines in it. Like a fence or a tree. Are the photos sharp?  If yes, there is nothing wrong with the Rebel."

After you determine whether it is the camera or something else we can possibly help you.

[ElleMo]

Ok, I will try that.  I was hesitant because the instructions sounded  to me that I should change what I am doing , "(forget that the green square ((or A anyting)) is even there)(never use it again" etc rather than a way to figure out what is going wrong.

I don't want to fiddle with settings when I am taking photos of a bunch people.  I want to use auto settings and they have worked well for years.  I look at similar pictures taken a few months ago and compare to one taken a few days ago (on the same computer screen) and many of the recent ones are blurry.  I had my friend take a few photos and she had the same issues so it's not me suddenly developing a tremor.

But I will try what you suggest and see how it goes.

[ebiggs1]

The recommendation of, " Now set it to P mode (forget that the green square ((or A anything)) is even there)(never use it again)." is my advice and will always be.

"I want to use auto settings and they have worked well for years."  OK, but if you never tried to learn how to actually use a DSLR, you don't know how much better your shots can truly be. But I am a big fan of, if you are satisfied with what you have, don't mess with it.  

Keep in mind, however, if you do the daylight test and it comes back OK, you do know what the issue is likely to be?

[ebiggs1]

ElleMo said,

"I've been using auto settings for years with no issues."

Perhaps you were just lucky.  Maybe you are becoming more critical.  Who knows?  Any of the fully A modes are the least desirable choices on a DSLR. The number one or perhaps second reason to buy and use a DSLR is the ability to adjust it to the shot and conditions. Interchangeable lenses is the other top reason. If you don't want these features you may as well use a P&S or iphone.

I urge you to learn exactly what each shot requires. You will be amazed at the results you can achieve with your Rebel.

[ebiggs1]

"... but the more recent pictures were outside on a nice weather days."

Here is what you should do.  First reset the Rebel to factry defaults.  Menus under tools clear all settings and clear all custom settings. Now set it to P mode (forget that the green square ((or A anyting)) is even there)(never use it again).

Go outside on a nice sunny day with the ISO set to 200 (not auto ISO, rarely to never use that either). Set WB to daylight.

Now find a nice contrast shot and try a few. Something with vertical lines in it. Like a fence or a tree. Are the photos sharp?  If yes, there is nothing wrong with the Rebel.

This means you need more specific settings to do your group shots. Av, set to f8, would be a good start.