100-400 mk1 - focusing

[Countryside59]

I have recently purchased a  7d mk2, the problem I am having when using the 100-400 mk1 is that Iam finding it difficult to focus manual or auto even in perfect lighting conditions, have tried various settings..does the lens need to be calibrated, Obtained some  crystal clear shots with the 5d.am aware the lens is rather slow to focus.

Any advice would be appreciated.

[ebiggs1]

I used a ef 100-400mm on a 7D for years and it performed flawlessly.  It should do so on your 7D Mk II.

Do you have the diopter in the viewfinder set wrong.  Set it to 0, or netural, and try.

The ef 100-400mm is a very good lens it is not a great lens, IMHO of course.  It served me well.  You need to seperate the two, canera and lens.  Get another body and try.  Get another lens and try.  Maybe you have another lens. Does the 7D Mk II work well with it?  If it does it is probably OK.  Does the 100-400 work well on a different 7D?