Excerpt: I just bought this to couple with my 17mm tse and 24mm tse and also on the 70-200 2.8 IS II and and completly not happy with any of the results yet. I'm a professional architectural photographer and this is significantly softening images and adding red and purple fringing on contrasting lines much like using a 18-55 kit lens or so. all my tse lenses are very sharp with no fringing.
Excerpt: It is interesting to see some complaints about lack of sharpness, especially on the EF 70-200mm f/2.8L USM. I am the first to admit, that the fore mentioned lens is an incredible work of engineering – and delivers excellent results independent of head behind the camera skill. Add the 2X extender and now you have a different lens. This lens is also brilliant BUT is less forgiving and head behind camera must adjust accordingly.
Excerpt: I purchased this to use with my 5DIII and 200-400 f/4. I was very hesitant given some of the very poor reviews, and because I've always read that image quality was significantly degraded with extenders, especially the 2X. My experience is that in the right circumstances any loss in image quality is more than compensated for by putting more pixels on the target. Like any long lens, this TC will not allow shooting at greater distances.
Pros: Consistent Output, Durable, Easily Interchangeable, Lightweight, Rugged, Strong Construction
You don't get all the benefits on the low f lenses.
4 weeks ago
Summary: I really enjoy shooting with this attached to my f2.8 80-200 lens. The only sadness is that it is limited to f 5.6. This is not a problem in the sun or other bright circumstances but is a problem with low light - especially when hand holding the shot
Excerpt: I purchased this item to use for whale, seal, and bird photography. I had read several reviews indicating that the photos taken using this extender were often a bit soft. I was also concerned that it was only compatible with certain lens/camera combinations. I recently had the chance to use it during a puffin and whale watch trip and was shocked by how sharp the photos turned out. I matched it with my Canon 300mm f/4L and Canon 1D mkIV.
Pros: Consistent Output, Nice Bokeh, Strong Construction
Excerpt: I bought this extender after considering having a longer reach, knowing in advance the loss of 2-stops of light, slower AF and some loss in IQ, however, I am still very please with the results in combination with my 70-200mm f2.8L IS II. I had the Mark II and I never got the results I am obtaining with the Mark III. Once installed, you should realise that the performance in low light will be pooooorrrr.
Pros: Consistent Output, Durable, Easily Interchangeable, Strong Construction