Excerpt: I use the Canon 1.4x III extender with my Canon 7D Mk2 and my Canon 100-400mm II lens. Superb detail with fast auto focusing but only the center focusing point works. So, now I am getting 896mm with sharp focus which is a tiny bit better than my Tamron 150-600mm at 960mm.
Pros: Consistent Output, Durable, Easily Interchangeable, Fast / accurate auto-focus, Lightweight, Nice Bokeh, Rugged, Strong Construction
Summary: I had a good copy, sold it because I thought I was done with longer focal lengths because my ef 400mm 5.6 was such a pita to use. This time around, paired with a new ef 100-400mm II, really glad I bought again. Getting very sharp images with bokeh just as good as when not used.
Excerpt: I purchased this extender to get a little more reach for my Canon EF 70-200mm f2.8L IS II. No degradation in autofocus performance noted on my Canon 7D Mk II. Very sharp when stopped down to f5.6. It's a great little addition to my bag wIithout the added weight.
Pros: Consistent Output, Durable, Fast / accurate auto-focus, Lightweight, Rugged, Strong Construction
Cost-effective way to increase the versatility of your lens arsenal
Michael Baxter, Amazon
6 April 2015
Summary: I read several reviews that convinced me to spend the extra cash on the newest (III) model vs. the previous two models. The quality is excellent. I specifically use it to extend the focal length of my two primary architectural lenses (Canon EOS 17mm and 24mm TS-E lenses).