I have the Sony 70-200 and it's without doubt a fantastic lens so when I read all these reviews on the 100-400mm saying how great it was and equel to the 70-200 I was really excited. When I finally got it t you could not believe how disappointed I was and have since returned it at a return cost $360 for restocking. It's nowhere near the performance of the 200 and for the cost it should have been as good as. Not once could I get it to outclass the 200, maybe the 400 was defective if so readers should be warned to test one before buying. The picture attached shows the upper picture taken at 400mm and the lower taken with the 200 at 200mm and then I zoomed 200 picture on the original, so as to get the same perspective and even having zoomed in it's clearly better than the 400 unzoomed as taken....the originals can be supplied...taken with the A7r2 Cheers