5D MK IV Auto Focus missing when Lens Stabilization is turned on. one lens only.

[PixelPurfect]

Recently, my images started getting blurry when shot with the 24-105 f4 L on my 5D MK IV.   It took awhile to realize it misses focus when I turn on IS on the lens.  I have tried other lenses, they are fine. I tried the 24-105 on my 5D MK III and it works fine, with or without the IS on. I am shooting a test pattern with the cameras on a tripod.  One other thing, the image appears in focus in the viewfinder, but not the capture raw file.  I did update the firmware to 1.4. 0. No joy!

Thanks!

David

[PixelPurfect]

Understood.

Thank you!

[ebiggs1]

"I do have the original 24-105. Maybe ten years old."

I have lenses that are 20+ years old and still working just fine. Matter of fact my Canon EF 28-70mm f/2.8 USM L is one of my sharpest zooms. It was released in 1993.

[ebiggs1]

"I've considered the reset."

Don't just consider it, do it. It could be the cause of your issues.

The act of mounting and removing the lens is most often enough to keep the contacts clean and working. Sometimes people have only one lens and they don't ever take it off. The contacts can become less conductive and a little alcohol on a qtip will help. If the contacts do become damaged they generally can not be repaired. Replaced is the only option and that may be cost prohibiting. 

[PixelPurfect]

Ok, I have reset to factory defaults. I updated the micro adjustments for that lens.  It's better.  Still have more testing to do.  I think it's most likely the lens and it should probably be refurbished or replaced.  We'll see.

That lens does stay on my MK4 a lot!

Thanks for you help!

[ebiggs1]

" I updated the micro adjustments for that lens. "

I would be very careful doing that. Most lenses do not need it nor do they benefit form it. The 5D Mk IV and the ef 24-105mm f4L make a fantastic combo I hope it all works out for you.