Sigma 2x converter on 70-200 2.8 sigma?

[Croasdail]

Next week I will be going down to the practice rounds for the US Open at Pinehurst to do some practice shooting. The one issue is they will not allow professional lenses or any mono or tripods on site for those days - so the 300 has to stay home. So I am planning on taking my Sigma and a 1.4x converter. I would like to get some more reach though and have thought of buying the 2x converter. In general I stay away from these, but my past experience has also been with lower quality converters as well. Has anyone used the 2x with the 70-200? Will it be $180 poorly spent? I can deal with MF is need be - but not poor image quality. Thanks!

[LightRules]

See my site: http://www.pbase.com/fstopjojo/70200s

The Sigma with a 2xTC will AF but it does produce some more CA than the 70-200 IS does. On most prints you'll be fine. Make sure to bring your monopod.

[condyk]

I used a Kenko Pro 300 1.4x with my ex SIgma 70-200 f2.8 and worked well. Less expensive and quality as good judging from user reviews. The Canon 2.0x seem not so good. I have a 1.4x Sigma and it seems very good, but only used it with my 100-300 f4 Sigma!

[CyberDyneSystems]

Focus wil still be Auto with the 2X and the f/2.8

Image quality goes down a lot with the 2X on that lens.. but it may be a
better than nothing opton.

[ScottE]

I have compare shots taken with my Canon 70-200/2.8 L and a 2x teleconverter to shots taken with my Sigma 50-500. The 50-500 is noticeably sharper. Similar results could be obtained with the Canon 100-400 IS.

If light was good, I would prefer to be shooting with the 50-500 and a monopod or the 100-400 IS hand held.

Scott

[Croasdail]

Dang and double dang.... I was hoping the converter would do the trick. I may get one and try it out anyway... but as this is an opportunity to shoot something that doesn't come around very often and I don't want to come back with marginalized images. Thanks all for your feedback.

[primoz]

I shot quite lot with 70-200/2.8 and 2x converter. I agree af gets much slower (even on my 1dmk2) but it's still quite fast and can easily manage 100km/h flying objects going 10m from you :) Also quality is worse then without converter, but for me it's worth. At least I can get photo which I wouldn't without. Same thing goes for using 2x with 300/2.8. Worse but when there's no other chance it will do its job :)