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

The 2x converter is excellent when you need some extra reach. I use with the 70-200mm 2.8 when I need extra reach, but still need the shorter minimum...

Excellent image quality

nothing

As represented above, Canon offers a huge range of prime (fixed focal length) lenses. Options range from ultra-wide angle through super telephoto and from tilt-shift through macro. There is a lens for practically every need included here.

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

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

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...

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

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

"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...

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