02-08-2017 03:01 AM
Hi,
My canon eos 600d won't autofocus, nor manually focus when I use the viewfinder but focuses properly when I set the display to the screen. What can be the problem? I already reseted the default presets and cleaned the sensors with the built in scleaner system. I have no more idea what to do.. Has something gone wrong in the camera or is it just a setting problem? I tried out to use autofocus in live and quick mode, in one shot and also in AI servo mode nothing changed..Thank You for helping!
Solved! Go to Solution.
02-08-2017 06:06 AM - edited 02-08-2017 06:10 AM
I'm not clear how it wouldn't manually focus, since that is you turning the ring on the lens with your hand.
Is the image in the viewfinder just remaining blurry and not resolving into a sharp looking view? If so check the tiny little diopter wheel on the right side of the viewfinder to see if it has gotten bumped out of focus. The diopter adjustment adjusts the viewfinder to your particular eyesight, giving you vision correction like glasses if you need it, so you can shoot without your glasses. If your dial is not set right, it is like looking through someone else's eyeglasses; totally blurry.
02-08-2017 06:04 PM
If you use the viewfinder do you hear the motors attempt to focus and then give up?
You may have dust blocking the focus sensors inside the camera. Your camera has two different focusing systems.
When you use the camera by looking through the viewfinder, the reflex mirror in the camera is in the "down" position so it can bounce light up into the screen in the viewfinder. But there's a section in the mirror that allows some light to pass through and then bounces it down into sensors that are on the floor of the camera. If the secondary mirror is damaged or if anything is blocking the tiny holes that let light into the focus sensors then the camera would not be able to focus.
When you switch to live-view, the reflex mirror swings up and the shutter opens. Since the mirror is now folded out of the way, it cannot bounce light down into the normal focus sensors. So instead it relies on something called "contrast detection" using the camera's image sensor to determine when you've achieved optimal focus. This focus system isn't nearly as fast and it usually has to do a bit of trial and error to refine focus (the normal focus sensors on the floor of the camera are much faster). But since this uses a completely different method to focus, it explains why you are still able to focus using "live view" mode.
Something might be blocking the focus sensors (e.g. dust). And if that's the case, the camera might just need a good cleaning. But it's also possible that either the focus system has failed or the secondary mirror is sticking and not correctly bouncing light into the focus sensors -- and that would mean the camera needs service.
02-08-2017 06:06 AM - edited 02-08-2017 06:10 AM
I'm not clear how it wouldn't manually focus, since that is you turning the ring on the lens with your hand.
Is the image in the viewfinder just remaining blurry and not resolving into a sharp looking view? If so check the tiny little diopter wheel on the right side of the viewfinder to see if it has gotten bumped out of focus. The diopter adjustment adjusts the viewfinder to your particular eyesight, giving you vision correction like glasses if you need it, so you can shoot without your glasses. If your dial is not set right, it is like looking through someone else's eyeglasses; totally blurry.
02-08-2017 09:32 AM
"I'm not clear how it wouldn't manually focus, ..."
Me either. Are your photos "blurry"?
02-08-2017 11:36 AM
@saravanda wrote:Hi,
My canon eos 600d won't autofocus, nor manually focus when I use the viewfinder but focuses properly when I set the display to the screen. What can be the problem? I already reseted the default presets and cleaned the sensors with the built in scleaner system. I have no more idea what to do.. Has something gone wrong in the camera or is it just a setting problem? I tried out to use autofocus in live and quick mode, in one shot and also in AI servo mode nothing changed..Thank You for helping!
What lens are you using? When you set the lens AF/MF switch to MF does the focus ring turn?
02-08-2017 06:04 PM
If you use the viewfinder do you hear the motors attempt to focus and then give up?
You may have dust blocking the focus sensors inside the camera. Your camera has two different focusing systems.
When you use the camera by looking through the viewfinder, the reflex mirror in the camera is in the "down" position so it can bounce light up into the screen in the viewfinder. But there's a section in the mirror that allows some light to pass through and then bounces it down into sensors that are on the floor of the camera. If the secondary mirror is damaged or if anything is blocking the tiny holes that let light into the focus sensors then the camera would not be able to focus.
When you switch to live-view, the reflex mirror swings up and the shutter opens. Since the mirror is now folded out of the way, it cannot bounce light down into the normal focus sensors. So instead it relies on something called "contrast detection" using the camera's image sensor to determine when you've achieved optimal focus. This focus system isn't nearly as fast and it usually has to do a bit of trial and error to refine focus (the normal focus sensors on the floor of the camera are much faster). But since this uses a completely different method to focus, it explains why you are still able to focus using "live view" mode.
Something might be blocking the focus sensors (e.g. dust). And if that's the case, the camera might just need a good cleaning. But it's also possible that either the focus system has failed or the secondary mirror is sticking and not correctly bouncing light into the focus sensors -- and that would mean the camera needs service.
02-19-2017 01:30 PM
Dear All,
Thank You very much Your help!
I did a reset again to all the standard setting, cleaned the system with the inner cleaner option and checked the diometer wheel again, and now my camera works fine. I hope it was only that I needed and there is nothing broken inside. I really appreciate your fast and detailed answers, those were really helpful not just resetting the camera but also to understand it a little better!
Cheers,
Sara
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