Disables autofocus (seems like a weakness, but actually makes sense).

I wanted to revise some impressions I noted in my initial review about this 2xTC. I first felt that results were mediocre when used with the Canon f4L. But I've since noticed that if stopped down to f11 (this would be f5.6 without the TC) then sharpness and purple fringing get MUCH better. So in bright sunlight, this lens+TC combination can deliver quality pictures after all. I also complained about how the Canon TC disables autofocus with my lens, whereas the cheaper models don't. I've since come to realize this is a blessing in disguise. With an effective max f8, autofocus is too erratic to depend on, and it SHOULD be disabled, to prevent one from trying to use it. Finally, I had originally complained that optically the Canon converter is no better than the cheaper brands. I still find this largely true, with the exception that some cheaper 2x converters "only" magnify about 1.8x or so, whereas the Canon is exactly 2x. In the end, I still think Canon's price is too high, but the factors lead me to upwardly revise my rating.

Image quality Build

Quite long Price Can't be used on many lenses

Like the 1.4x converter this is expensive but works really well with Canon 'L' lenses... or at least it does with the 70-200L I have. I haven't had it long but have taken alot of shots and certainly enough to be well impressed with the quality for what it is. In terms of it's effect on the autofocus it will hunt a bit depending on light conditions and you loose a bit of speed but I don't think it is too bad at all. Not quite as good as the 1.4x but still impressive.

Customer Service

Not used.

Similar Products Used:

Canon 1.4x converter

* AF performs very fast with my combo (70-200L f/2.8) when used in good light conditions. * The money spent to get a super telephoto lens (400mm f/5.6) keeping the versatility of the zoom. * Perfect for telephoto "L" lenses.

xxxx

I use this high performance extender with my 70-200L f/2.8 with very good results. The image quality is preserved. It increases the focal length by 2 times and decreases the f-stop by 2 sops. The lens becomes a 140-400L f/5.6. AF is possible with my EOS 3 and my EOS 50e. I don''t regret each pound...

Customer Service

xxxx

Picture quality. Good Af speed (when used in sunny conditions) Build and look. Price at the moment.

AF suffers in poor lighting conditions.

Brilliant 2x extender. I use it with the 300 f2.8L, which makes it a 600 f5.6. Which is nice!! Af speed does suffer a little - but as I shoot Formula 1 cars, I would notice alot. But for other subjects it would be fine. Picture quality is extremely good - even when the slides are viewed under an 8x loupe. In short...it makes the 300 a great 600 f5.6 (and quite alot cheaper than a 600 f4!!!)

Customer Service

never needed

Similar Products Used:

Canon 1.4x Sigma 1.4x

Perfect co-operation with appropriate Canon L-line lenses in terms of AF-speed and sharpness.

Very little vignettig when used wide open with 200/2.8. No way to use it with not-L-lens.

IMHO, very great deal. I use it excessively with EF 200/2.8 L and there is just a small quality deterioration when used wide open, rather more vignetting (but still more than good to my requirements, far superior to Sigma 70-210/2,8 EX HSM + Sigma TC 2x) than loss of sharpness. AF performs very fast with this combo when used in good light conditions. At low light, AF may "hunt", especially when the focusing range of the lens is not limited.

Customer Service

Not needed

Similar Products Used:

EF 24-85/3.5-4.5, EF 50/1.8, EF 200/2.8 USM L