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My Canon Rebel SL3 (EOS 250D) Won’t Focus – 8 Solutions

Camera’s arent cheap, so when they don’t work as they should it gets annoying. 

One of the most annoying things is when your camera just won’t focus and the last thing you want is for your autofocus to stop working in the middle of a shoot. 

The Canon Rebel SL3 (also known as the Canon EOS 250D) is a solid crop sensor camera for people to get started and most of the time you’ll never have a problem. But every camera can have its problems one day. 

When I had issues with the Rebel SL3 not focusing I was so annoyed, but I scoured the internet to fix my problem. 

I tried everything out there but number 8 on this list was my solution. Hopefully, using this list of solutions you can find out why your SL3 is not focusing. 

To give you a quick summary here’s the list:

  1. Check Your AF/MF Switch
  2. Your Subject Is Too Close For Comfort
  3. Your Lens Isn’t Attached Properly
  4. Clean Your Contacts
  5. You Need More Light
  6. Your Subject Is Too FAST
  7. Not Enough Contrast
  8. Custom Function Settings

1. Check Your AF/MF Switch

This one is so easy, you’ll probably feel bad if this fixes your problem. 

When using your Canon lenses with your Rebel SL3 you’ll notice that there’s a small switch on the lens to switch between autofocus and manual focus.

The switch will say AF/MF and it’s quite easy to find on your lens. See the picture below to see what I mean.

AF/MF Switch on Canon Lens

You might be trying to autofocus with your camera, but you’ve left this switch on MF so your camera is having none of it.

As far as your trusty SL3 is concerned, you want to be using manual focus. 

To fix this, make sure the switch on your Canon lens is set to AF and not MF. 

Remember that this is not to do with auto vs manual mode in terms of exposure and other settings that affect exposure. This is just auto vs manual mode for focus.

2. Your Subject Is Too Close For Comfort

If you’re too close to your subject then your camera and lens will not be able to focus. 

The reason for this is that there’s something called a minimum focusing distance. All lenses and cameras have this. 

All it means is that whatever you are photographing has got to be a certain distance away from your camera. 

To be precise, it has to be a certain distance away from the focal plane which is where your sensor would be in your Rebel SL3. 

It can be hard to notice the focal plane mark on your SL3 if you don’t know what you’re looking for.

On mine it’s like a small black engraving which looks like a small circle with a line going through it. Kind of like the London Underground logo. 

To find it, do this:

Put your camera down with the lens side facing away from you. Now look at the top of your camera. On the left hand side you should see the small holes for the speaker. 

To the left of these speaker holes you’ll also see the focal plane mark. 

Now you just find out your minimum focusing distance and keep that focal plane mark at least that distance away from whatever you want in focus. 

Different lenses have different minimum focusing distances so you should double check depending on what lens you have. 

Here are some minimum focusing distances for popular lenses on the Rebel SL3:

As you can see, the minimum focusing distance can vary quite a bit depending on the lens you are using, so try to find out what it is for your lens and you should know whether this is the problem or not.

Luckily, this is an easy fix.

Just step away from the subject until you have enough distance from it to focus. 

If your Canon EOS Rebel SL3 still can’t focus then try one of the other solutions. 

3. Your Lens Isn’t Attached Properly.

Autofocus only works because the lens and your Rebel SL3 communicate with each other. 

They can only do this if they’re attached together properly because there are some metal contacts that allow them to communicate.

Now if you’ve not put your lens on your camera properly and the contacts are not aligned then they can’t communicate and you’ve got no autofocus. 

So take your time and put your lens on your camera properly. 

Attach your lens correctly to your SL3 by doing the following:

  1. Find the white square or red dot on your lens and match it with the same white square or red dot on your camera body where the lens mount is.
  2. Now attach the lens and rotate it until the lens locks into place. 
  3. The lens should click into place and not be loose. 

If you think that this doesn’t feel right you might have a screw loose (ok not you, but your camera might).

An easy way to tell if it’s an issue with contacts on your lens is to use a different lens. If a different lens works fine then it’s probably an issue with just one of your lenses. 

If there is an issue with your lens then get it checked by a service center. You could try a local camera shop, or go through Canon directly if you want to lose your life savings. 

If you have reattached your lens and it seems fine but autofocus still isn’t working then it’s probably another issue in this post.

4. Clean Your Contacts

Like we said in the previous issue, the lens and camera communicate through metal contacts that let your camera autofocus. 

If these contacts get too dirty it can stop the communication between the camera and lens, and hey presto, no more autofocus for you sir/madam.

If you can see that they’re dirty, get them cleaned by a local camera shop. 

Otherwise try it yourself if you feel like saving some money. But if you choose this route you have to be super careful. The last thing you want to do is ruin your camera further. 

Below are some cleaning instructions directly from this Canon support page. (the support page is for the 80D, but the 80D and SL3 are both DSLRs that work in a similar way so the same can apply).

“If the lens contact and camera contact are dirty, transmission will not occur normally and autofocus might not operate correctly.

If the lens and camera contacts are dirty, wipe them with a clean, dry cloth, being careful to not scratch the contacts.


Cautions when Cleaning the Contacts

  • Do not wipe the contacts with a wet cloth. Doing so could cause malfunctions.
  • Do not touch the contacts directly by hand. Doing so could cause corrosion, and cause the camera to stop operating.
  • When cleaning the lens contact, be careful to avoid scratching the lens surface.
  • If the contact area is particularly dirty, contact a Canon customer service center for assistance.“

If this isn’t the solution to your problem, keep reading and see what else the issue could be. 

5. You Need More Light

When there’s not much light in a scene, the Rebel SL3 can find it hard to focus because there’s not much contrast between light and dark. I mean it’s just dark.

Solve this easily by adding some artificial light to the scene:

  • Shining a laser on the subject where you want to focus (DO NOT point this at someone’s eyes) 
  • Turn a flashlight on and point it at the subject
  • If the subject is a person then ask them to hold a smartphone screen up. 
  • Use lighting such as an external flash or a softbox.

The video below demonstrates some of these tips above.

If you are using the flashlight, laser, or smartphone trick, you are mainly using these just to lock the focus in the same focal plane as your subject. 

So you’d make sure the artificial light is in line with your subject in this case. 

You would then turn the light/laser/smartphone off and take the photograph with the correct exposure. 

If you’re just adding light in general across the scene like with a softbox or external flash then just photograph as normal.

This was one thing that always annoyed me when I started out in photography and quickly learnt to make sure I have an external flash with me or I use a softbox when at home. 

6. Your Subject Is Too FAST

If your subject is an F1 car, then good luck. Those things are fast. And fast moving objects are much harder to autofocus on.

But it depends…

It’s only really an issue when the subject is crossing different focal planes. 

If something is moving parallel to you, it’s always in the same focal plane relative to you. 

On the other hand, if it is moving further away from you or closer to you then it’s constantly moving across focal planes – this is where it can be an issue if something is moving fast. 

For example, photographing birds or sports-people can be a pain because they’re somewhat unpredictable and can move in different directions at speed. 

By the time your Canon SL3 can focus, the subject’s already gone and left the focal plane your camera focused on. 

One simple fix is to check that you are using the correct autofocus mode. 

On a Canon Rebel SL3, you can pick from different autofocus modes.

You can use One-shot, AI Servo or AI Focus. By default the Rebel SL3 will be in ‘One-shot’ mode so change this to AI Servo mode if you are photographing moving subjects.

This is because AI Servo will continuously track a moving subject to focus. 

To enable this you can do the following:

  1. Go to your in camera menu on your SL3.
  2. Go to your shooting settings menu, this is a red menu with a camera icon.
  3. Go to page 6 of your shooting settings menu. 
  4. Select AF operation. 
  5. Then you will be able to choose between One shot, AI Focus or AI Servo. 

Alternatively you can also press the ‘Q’ button for your quick menu, select the focus option then choose AI Servo from there.

The video below explains this concept and also shows you how to do it on a Canon camera as well as a Nikon camera.

7. Not Enough Contrast

Similar to the earlier issue where I said that the camera will struggle to focus if there is not enough light, the camera can struggle if there’s not enough contrast too. 

But what do I mean specifically?

Think about a subject where there’s not much texture or change in colour. 

For example, a perfectly clear blue sky or a smooth flat surface made of one solid colour. 

Since there’s not much contrast in these scenes your SL3 may find it difficult to autofocus because contrast detection helps in the autofocus process. 

8. Custom Function Settings

Maybe you’ve pressed some buttons by accident.

Maybe you bought your SL3 second hand and the previous owner had a different take on life.

Or maybe someones playing an elaborate prank on you.

Whatever it is, somehow your ‘Custom Function’ settings might have been changed and this could be stopping your Canon Rebel SL3 from autofocusing as expected. 

Let’s fix that:

  1. Go to your Menu and navigate to the yellow wrench tab in your menu. Which is also known as the ‘set up’ menu. 
  1. Go to the 5th tab under the ‘setup menu’. It should say ‘set up5’ in the top right corner of your screen. 
  1. You should now see the Custom Functions (C.Fn) option. Select this. 
  1. You can press the right and left arrow on your camera to move between the different other custom function menus.
  1. You should also see 2 rows of numbers at the bottom left of your screen. The top row of the numbers is the custom function and the bottom row is telling you which option you have selected for that custom function.
  1. You want to navigate to ‘C.Fn III: Operation / Others Shutter/AE lock button’ which is custom function number 7.
  1. You should see 4 options as follows:
    • 0; AF/AE lock
    • 1: AE lock/AF
    • 2: AF/AF lock, no AE lock
    • 3: AE/AF, no AE lock
  1. If this list is gibberish to you, don’t worry, just make sure that your camera is set to one of the following:
    • ‘0: AF/AE lock’ (which is the default for the camera)
    • ‘2: AF/AF lock, no AE lock’
  1. Now try taking images as normal and it should hopefully work.


By working through each of the issues on this list you probably have fixed your autofocus problems on your Canon Rebel SL3. 

If not, I’m sorry, but this is where my help ends.

If you’re still having issues then you probably want to send your SL3 and/or lens into a camera repair shop or a Canon Service center to get it looked at. 

Related Reading:

If your friend asked you whether the Rebel SL3 had an external mic input, would you know?

And if you’re ever going to be recording any video on your SL3, you should also know that the Rebel SL3 has a recording limit.