Recently have been having some weird AF issues on my A7iii

[Peteryunsie]

I have been having some AF issues recently that comes up randomly but not often.  The camera sometimes struggles to focus on what seems to be a pretty easy subject to focus on and starts “focus breathing” (Not sure if this is the correct term) really fast and the camera is unable to focus on the subject.  Sometimes, when shooting a person, the camera shows the square box over the subjects face to show it is recognizing a human and turns green but the subject isn’t in focus and the AF just starts breathing really fast again. I have tried on my different lenses and the issue still persists.  In the video I believe I had my Tamron 28-75 lens on and from my googling the minimum focus distance is 7”, my camera was about 2 feet away from the subject.  Has anyone had this issue before?  This issue doesn’t come up that often but when it does it’s really annoying because it takes a while for me to focus on what  I need to.  
 

 

 

AF issues example

Example 2

 

 

edit:added another example

Edited March 11, 2023 by Peteryunsie

[Pieter]

First one seems to be related to minimum focus distance. The minimum focus distance of 7" is only at 28mm focal length. At longer focal lengths, the minimum focus distance increases. You seem to be zoomed in and pretty close to the subject.

Second one unclear. The subject moves a lot and face moves out of the frame, could give some struggles to the camera.

Does the problem also occur on stationary subjects further away?

[Peteryunsie]

On 3/12/2023 at 6:15 AM, Pieter said:

First one seems to be related to minimum focus distance. The minimum focus distance of 7" is only at 28mm focal length. At longer focal lengths, the minimum focus distance increases. You seem to be zoomed in and pretty close to the subject.

Second one unclear. The subject moves a lot and face moves out of the frame, could give some struggles to the camera.

Does the problem also occur on stationary subjects further away?

Yeah the first one wasn't at 28mm, don't remember what it was at, so I guess  that could've been the issue.

Second example:  Could be, but just weird how it'd glow green to say it was in focus when it wasn't in focus, that night I was trying for a while for the camera to focus on any of my friends and it was struggling even if they weren't moving much.  

Can't remember if it happens on stationery objects or not. 

[Lauren-]

Hello Peteryunsie! 
I encounter the same problem (first example with a focus breathing which should not happen) while filming. 
Did you find a solution? Do you know where it comes from?
Thanks a lot for your answer.
Lauren

Edited March 11 by Lauren-

[Cameratose]

2 hours ago, Lauren- said:

Hello Peteryunsie! 
I encounter the same problem (first example with a focus breathing which should not happen) while filming. 
Did you find a solution? Do you know where it comes from?
Thanks a lot for your answer.
Lauren

Lauren, that user hasn't been here for almost two years. In answer to your question, the description of what he calls 'focus breathing' sounds more like 'hunting', where the camera can't find focus so it 'hunts' back and forth. There can be a couple of reasons for this, Pieter describes one above. Another can be too low of a light source. These cameras need enough light to see the subject, and enough contrast to find focus. Depending on the camera, that amount of light varies. The A7 IV, for example, is rated better in low light AF than some of the earlier models.  

In order to stop the camera from making a shot when out of focus, go into the menu and turn on 'release on focus' so it only makes the shot when in focus. If you leave the release on 'balanced' it will sometimes take a shot even if not in focus. 

[Lauren-]

Thanks for your reply Cameratose. I brought the camera to a fourth shop, they noticed that something was wrong and I hope they will be able to fix it.