cancel
Showing results for 
Search instead for 
Did you mean: 

Autofocus Points manually selected, but incorrect?

lem0nster
Apprentice

I've been shooting with my T4i and 50mm 1.8 for almost a year now, and recently, it's autofocus is on the fritz. I manually select an autofocus point, but for some reason, it autofocuses on somewhere OTHER than the point I have selected.

 

Is this an issue with the body or with the lens?

1 REPLY 1

TCampbell
Elite

Are you saying it's "missing" the focus... or are you saying it's actually using a different focus point.  Those would be two different issues.

 

If you open an image shot by the camera using the Canon Digital Photo Professional (it came with the software included with the camera), open the image, and then right-click to expose the pop-up menu.  There is option to show the focus points.  This will cause DPP to put an overlay on the image showing the familiar focus point pattern, but it will highlight the specific focus point (or points as the case may be) which the camera actually used.

 

This would help you determine if the camera is actually using the point you asked it to use.

 

It's entirely possible it's using the point you've asked it to use, but the shot is still coming out blurred - and there can be many reasons for this.

 

If the subject was moving and focus distance was changing, and if you were using the default "One Shot" drive mode, then the camera will focus until it gets a focus lock and then it will STOP focusing... even though the subject may still be moving.  In essence the camera is focused at the point where the subject used to be at time of focus.  So you'd want to make sure you are doing a test on a non-moving subject.

 

If you use AI Servo mode (normally used for action photography), then the camera WILL take the shot when you fully press the shutter button -- even if it did not have time to focus.  That mode take the photo WHEN you tell it to... no exceptions.  It's for photographers who want to capture the "decisive moment" and don't want the camera to lag at all.  You have to half-press the shutter to pre-focus before fully pressing the shutter if you want to ensure the sujbect is focused AND in that mode... the focus system remains active even after it locks focus (it keeps re-tweaking focus so that a moving subject will be continuously re-focused.)

 

And then you can get blur caused by camera or subject movement -- so it looks blurred but not for lack of focus.

 

There is also the possibility that the camera is missing focus... and testing needs to be done to determine if this is the case (you'd find and print a focus chart and do some testing... before going down that path, let's see if we can isolate another reason for your out-of-focus images.)  I'm somewhat fussy about how focus testing is performed because I want to eliminate any possibility of operator error to ensure that the only reason for a missed focus would have to be the equipment.

Tim Campbell
5D III, 5D IV, 60Da
Announcements
06/30/2022: Service Notice: EOS 70D: Error 70 or Error 80
06/10/2022: Service Notice:UPDATE: Canon Inkjet Printer continuous reboot loop or powering down
06/07/2022: New firmware version 1.3.2 is available for PowerShot G7 X Mark III
06/07/2022: New firmware version 1.0.3 is available for EOS M50 Mark II
05/31/2022: Did someone SAY Badges?
05/26/2022: New firmware version 1.0.5.1 is available for EOS-C500 Mark II
05/26/2022: New firmware version 1.0.3.1 is available for EOS-C300 Mark III
05/10/2022: Keep your Canon gear in optimal condition with a Canon Maintenance Service
05/05/2022: We are excited to announce that we have refreshed the ranking scale within the community!
04/26/2022: New firmware version 1.0.1.1 is available for EOS R5 C
03/23/2022: New firmware version 1.0.3.1 is available for EOS-C70
03/22/2022: New firmware version 1.2.0 is available for PowerShot PICK
03/16/2022: New firmware version 1.5.2 is available for EOS-R5
03/16/2022: New firmware version 1.5.2 is available for EOS-R6
02/09/2022: Share Your Photos is back!
02/07/2022: New firmware version 1.1.1 is available for EOS-R3
02/07/2022: New firmware version 1.6.1 is available for EOS-1DX Mark III
01/19/2022: READY FOR ANYTHING EOS-R5 C
01/13/2022: Community Update. We will be retiring the legacy profile avatars on 01/20/2022. Click this link to read more.
01/05/2022: Welcome to CES 2022!
12/7/2021: New firmware version 1.3.0 is available for Mount Adapter EF-EOS R 0.71x
12/7/2021: New firmware version 1.1.1 is available for CR-N 300
12/7/2021: New firmware version 1.1.1 is available for CR-N 500
12/2/2021: New firmware version 1.1.0 is available for RF 70-200 F4 L IS USM