by Jeff Medkeff

I love this extender. Its a bit expensive, probably Canon Extender EF 2X II is most logical to get. I did not own previous extender so I cannot compare them. This is my first extender, works like a charm, love it.

Durable; Easily Interchangeable; Quality; Strong Construction

Expensive; Heavy; Inconvinience

We reviewed the Canon 400mm ƒ/5.6L USM back in 2008, which makes a good candidate for comparison with the 200mm ƒ/2.8L USM and 2x Extender attached. In terms of sharpness, the two are quite similar: the 400mm is slightly better at ƒ/5.6 and ƒ/16, but at ƒ/8 and ƒ/11, they're almost identical.

Tested this like 5 weeks ago. The Extender 2x III performs better on my 70-200L IS Mk2 than on the Mk1. There is a noticable difference in AF and IQ. I had them side by side. The Extender 2x III gave no improvement on the 70-200L IS Mk1 over the Extender 2x II. I got the Extender 2x III in the end.

Good build; good image quality; still fast AF

price

"If you are putting this on a high quality lens then it is a good way to get a lot of extra telephoto reach without taking up much room in your camera bag. Images when used with a great lens such as the Canon 70-200f2.8L IS II are very good and certainly a lot easier then carrying a 400mm lens as...

Works verry good with the 300 mm F2.8 L IS USM II and the 70-200 mm F2.8 L IS USM II . Sharp pictures and AF works excellent. http://www.panoramio.com/user/971669 http://www.hdr-photography.be

Cons

Works verry good with the 300 mm F2.8 L IS USM II and the 70-200 mm F2.8 L IS USM II

When I first tested this against the Mk2 extender for IQ with static indoor test subjects, I thought I had made a mistake in spending so much in that the differences in IQ other than in the mid / corners did not seem that different.

Cost effective solution as works superbly with my 70-200 2.8 Mk11; much better contrast / saturation and tighter fit than Mk11 version

Images are slightly degraded and will always be compared to equivalent length alternative lenses

Tested on 5D MkII and 70-200 Mk II Do your research, you are going to lose autofocus speed, a little bit of image quality (depending on what you pair it with). Saying that I was comfortable with the images coming out, I had the benefit of not having to shell out for a 300mm or 100-400mm and carry...

I photograph minor league baseball and this allows closeups of the outfield or field shots from the upper level coupled to my 70-200 L series lens. I am not a professional and use of this lens allows great reproduction for families, players and fans.

High Quality; Well Made

Heavy

good add on for F2.8 lens. Focusing is slow but end result is sharp. I am using on my Ef200mm f2.8 lens.

Durable; Easy To Use; Reliable

Bulky