Excerpt: I periodically shoot crew rowing regattas and the boats are typically 100+ yards away. The 2X extender works great with my 70-200 lens and the shots are quite sharp. The recent $[$] price break makes the economics of the 2x versus buying a new, longer lens that more compelling. Contrary to some negative feedback I've seen I haven't experienced slowness with the autofocus. I do tend to use a monopod for extra stabilization.
Excerpt: Used the extender the day I received it and picture quality and AF speed is good. I've always had a great experience buying all of my camera supplies from B&H. They are honest and dependable. They do what they promise. Highly recommend.
Pros: Easily Interchangeable, Fast / accurate auto-focus, Lightweight, Strong Construction
Excerpt: I have been considering a doubler fr some time. And upon unpacking it I was not dissappointed. The.quality and workmanship are excellent. The price was more than the aftermarket doubters, but over the years I have found that you get what you pay for. So I don't cut corners. The picture quality through my EE 100-400mm f/.5-5.6 L IS UMS lens is more than I had hoped for.
Excerpt: The 2x Extender is a good selection for those who need the longer focal lengths, but are not ready to commit to the higher prices. The draw back of course is the loss of two stops, but can work around those. Also helps my main lense is f2.8. My test results were good and will use this extender again.
Excerpt: As other reviews indicate, there is a loss of light (on the 135 mm 2.0, it becomes 270 mm 4.0)- this being understood, having the availability of such powerful magnification/telefoto is fantastic. For myself, the 70-200 2.8 is needed for more flexibility, and with the 2x it means 140-400mm- plus, due to working with a crop-sensor 70D, it yields a whopping 224mm to 640 mm.