Excerpt: it's an excellent way to increase the focal length of the selected Canon lenses. The image quality is excellent with my 70 to 200 F for lens. I highly recommend in as an alternative to a second lens.
Pros: Easily Interchangeable, Lightweight, Strong Construction
Excerpt: Extenders have always been questionable to me. When you have a high quality, expensive lens, you don't want image quality degraded in order to increase focal length. The only compromise I can see when using the Canon 1.4X III extender is that you lose an F stop. But I don't see any loss of image quality when using the 1.4 with a Canon EF 135 F2 lens.
Pros: Consistent Output, Durable, Fast / accurate auto-focus, Lightweight, No Image Quality Loss, Rugged, Strong Construction
Excerpt: I used the extender to shoot softball with my 70-200mm f/2.8 IS II zoom on my 5D3. The extender worked flawlessly: the 5D3 focused just as accurately as without the extender & exposure was set accurately. It fit the lens & camera perfectly just as you'd expect for a Canon product. The effective 280mm maximum focal length worked fine for shooting action in the infield, but wasn't long enough for the outfield.
Pros: Consistent Output, Easily Interchangeable, Fast / accurate auto-focus, Rugged, Strong Construction
Excerpt: It simply snaps on between your lens and your camera. I use this 1.4 on a 5D + 70-200 setup. I shoot from about 8 to 35 yards from my subjects. The 35 yard shot was not selling too well because it was just out of range of interest. By range if interest I mean the subjects could just barely tell it was themselves. So I needed to reel them in another 15 feet or so.
Pros: Consistent Output, Durable, Easily Interchangeable, Fast / accurate auto-focus, Lightweight, Nice Bokeh, Rugged, Strong Construction
Excerpt: I use this with my 70-200 2.8 IS ii and 7D. I have been very pleased with this combination. It helps me out with some extra reach for photographing waterfowl and small-medium size approachable birds. Autofocus is quick and the resulting images are very sharp.
Excerpt: I haven't had much opportunity to use the item yet, but fully expect it to work with a 100-400 Canon zoom lens I will be receiving in a couple days. I've always had good service ordering from B&H.
Excerpt: The extender turns my 70-40,f.4 L lens into a 280 and with my Canon 50D. It worked great for a couple of my granddaughter's softball games -- sharp focus, action frozen, shutter speeds up to 800 to 1000 in both bright mid-day light and even into the early evening. Since my shooting will be mostly these events and being close to the action on the field, the extender is all I need.I have yet to try it with some landscape and wildlife shooting, but if it is done in brighter...
Pros: Consistent Output, Easily Interchangeable, Fast / accurate auto-focus, Strong Construction