When the 5D3 came out it had a bug. AF microfocus would default to ALL-8 for all lenses. FW 1.2.1 was suppsoed to have corrected this.
I knew all AFM setting were at 0 becuase the EXIF data shows this. I sent my camera to Canon in early June. I got it back and did a grad in late June. Still at zero when I recently checked.
Did an engagement in early September and the images using my 70-200 2.8 V2 looked off. I kept looking at them from time to time. The other day I checked the cam and it was set to ALL -8.
I checked some of my vacation shots from July/August and again ALL-8. I have not touched the AFM adjustments since March.
I posted this on DPreview and POTN. A few people responded at DPreview that 1.2.1 has not completely corrected this.
Here is a post from POTN
Just checked my 5D3, all set to -8 (FW 1.2.1)
No wonder my Sigma 35 was constantly producing off shots. Funny thing is I did remember seeing -8 before without realizing this is a known issue, I didn't pay much attention and just set it back to zero at the time despite I was pretty sure I didn't set that value. Now that I've just checked it's on -8 again...
I asked if the FW was 1.2.1
As said, I changed it back to zero when I saw it.
Then saw your thread and thought you know what let's check it again, and I see -8
So I just thought I'd throw this one out here and see what happens
No it appears it has not been properly fixed by the update. I have had the issue again and have heard that others have too - but it seems not all cameras were affected in the first place.
All a bit odd and annoying, especially when you didn't write down all your MA settings like I didn't (initially, I have now)
Thanks for writing in! We've had our engineers here in the US look into this and we've confirmed that Firmware version 1.2.1 should have corrected intermittent issues where the microadjustments for ALL are being set to -8 randomly.
Since you've already confirmed this update has been applied, we'd suggest contacting Canon Canada to have your EOS 5D Mark III checked out to see if something else might be amiss.
We hope this helps!
Thanks for the reply. I am a Canada CPS member but I have not had good success with Canon Canada Service. New Jersey has always been outstanding and I'm not even a member. Only issue is that I have to pay for shipping to New Jersey and Canon Service USA does not ship back to Canada so I use a USA shipping address.
If I have any other reason to send my 5D3 for service I'll have them look that this. Not worth sending it to the US for that and avoid trying to deal with Canon Canada on anyting critical. They do a good job replacing broken battery doors but anyting to do with camera performance is a crap shoot. For now I'll just keep an eye on it.
09/26/2023: New firmware updates are available.
08/18/2023: Canon EOS R5 C training series is released.
07/31/2023: New firmware updates are available.
05/31/2023: New firmware updates are available.
05/18/2023: New firmware updates are available.
03/30/2023: New firmware updates are available.