Good morning I seem to have a problem with the autofocus not working properly ,I used the lens attached to a Canon 90D a couple of months back at an air show and after a while auto focus stopped working,Switched off and changed battery and all was well for a while. Used this combination a couple of days ago and same thing happened.Switched camera off but the top screen was still live.Had to change battery to get it going again.I wondered if it was a camera issue not liking the lens but have used in the past without issues.Camera also works correctly with my Sigma 24-70 attached.Tried lens on my 7dmk2 and everything seemed ok but after a while focus wouldn,t work but resumed after I switched off and on again.Also screen went dark before being able to see the through the viewfinder.I'm assuming the lens is the problem.H as any one come across this before please? Many thanks.
