6D autofocus irregularity

[Bucksflyer]

I have a 6D plus 24-105

Last couple of weeks in P mode the camera does not focus and keeps hunting from sharp to blurry.

Anyone know the cause and a fix?

[JohnLo]

I reset everything. I changed to my 24-70 with the IS Off (from my 16-35) and it still randomly jumps from one focus position to another.

[JohnLo]

I should add that I bought the camera used off CraigsList because it was in beautiful and only had a shutter count (using EOSInfo) of about 4500. The serial number is: 032024003551. I have no idea whether you can determine the age from the SN. I don't know where it was originally purchased. I filled out a service request form but I have no idea what it will cost me.

[ebiggs1]

Keep in mind that lenses focus.  The camera doesn't focus. It just tells the lens when it is in focus.  If you tried several lenses and still don't get accurate focus, than something is wrong with the 6D. But make sure you try several different lenses under ideal conditions.  Out doors on a nice sunny day after a factory reset of the 6D.  Set it to One shot, not Ai-servo mode.

[JohnLo]

I sent it to Canon today. We'll what happens.

I understand that the optics in the lens moves to achieve focus but the body determines focus and tells the lens to move. The focus is controlled by the body. The phase and contrast detection sensors are in the body. It seems my 6D is sending instructions to the lens when it should be sitting on standby waiting for me to push the shutter button half way down.