EF Extender 2x III

Does what it is meant to do. Exellent build Canon at it's best.

None what so ever.

I bought this to go with my 70-200 USM II and it is the perfect addition giving me a 400 MM zoom now. Yes, you lose a couple of stops and you can only go down to F5.6 with it on, but its still great and much cheaper than buying a a 400 mm lens. Images...

Quite heavy. Doesn't fit all of my lenses though, only the L-Series.

Canon do not make it clear the the autofocus will not work whent the fstop is 8 or above, meaning NO autofocus with most lenses. This needs to be much clearer in the advertising as it does advertise full autofocus.

Boost to my 70-200 2.8 L lens,good quality photos if you do no cropping,brilliant on Video use.

No bad points really,a little disappointed in picture quality when cropping.

Extends the focal length significantly. Much cheaper than buying a 2nd HQ lens.

Dark - f5.6 at best on a 2.8 lens, f8 on anything less fast/open. Less focal sharpness. These really need bright conditions to work reasonably well.

Used in combination with a 70-200mm f/2.8 the image quality is fantastic. Autofocus is fast and accurate.

Quite a high price but cheaper than buying another L series lens.