focus trouble or me

[Dm1973]

Hi all 

a7r3 I've had for a while now and ticks all the boxes apart from photographing dogs while they are running towards me. I've tried this with 100-400mm and the 24-70mm. both wide open .Used in continues fire,  I've tried all focus modes and lock on, but it seems the first image is normally spot on but there after all images are out of focus, shutter speed will be dependant on the day but 1/2000 or higher if i can. iso again dependant on the day. I'm normally on the ground at eye level so the dog should stand out on an open field or the beach. 

In lock on you can see the box following the dog but the images are not in focus.  

 

Manny thanks. 

[Heldoorn]

Are you sure you were wide open? Manual states that at above f8, the focus will only lock on with the first frame. Also look at shooting in compressed instead of uncompressed and try High instead of High+