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11-13-2009, 04:14 PM   #1
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Sigma 100-300 f/4 EX DG

I am buying one of these and was considering whether to add a 1.4X, 2.0X, or both teleconverters. I see Sigma says the 1.4X will work in AF but that the 2.0X will only work in MF. Anyone had any experience using the 2.0X? Is there a way to make it work in AF? Does the 2.0X degrade the image quality as compared to the 1.4X?

Appreciate any comments / experience in this regard.

11-13-2009, 04:32 PM   #2
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Sigma 100-300 is an excellent choice. It works well with the 1.4 TC. I haven 't tried the 2X TC, but I would recommend against it (I've tried other brands, and was able to capture an image that got into PPG - still not really a viable option, too many duds and very very few keepers). IQ certainly suffers a lot and the resulting f8 min. aperture is very slow as well. As you know even the 1.4 TC will degrade IQ a little, but surprisingly very usable.
11-13-2009, 06:42 PM   #3
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I am planning on getting this same lens. I chose it instead of the Bigma because of the IQ being better. That said, I have the Tamron 1.4x that I plan to use with it and will also buy the Sigma 2x. I have heard both good and bad things about it but I have also heard good and bad about the Tamron. I feel that the lens itself is high quality and the matched 2x teleconverter should not hurt the image quality too badly.
11-13-2009, 07:15 PM   #4
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I had the Sigma 1.4 TC and sold it when I got the Tamron 1.4 TC so I think the Tamron is better, but the Tamron's are very hard to find, and this Sigma's do a good enough job. I find cropping better than 2X TC's.

11-13-2009, 07:58 PM   #5
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I also use the Tamron 1.4 with my 100-300 and like it alot.
11-14-2009, 02:34 AM   #6
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doesn't the kenko 1.5x shq teleconverter work as well, almost or just as good as the tamron ?

trying to get a teleconverter for the 100-300mm too.
11-14-2009, 05:30 AM   #7
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Using a 2x TC will decrease the aperture by 2 stops, so the 100-300 F/4 effectively becomes a 200-600 F/8. Most AF systems tend to only work effectively up to about F5.6, any smaller, and there's not enough light for the AF system to work effectively.

Last edited by pop4; 11-14-2009 at 05:41 AM.
11-14-2009, 11:37 AM   #8
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QuoteOriginally posted by pop4 Quote
Using a 2x TC will decrease the aperture by 2 stops, so the 100-300 F/4 effectively becomes a 200-600 F/8. Most AF systems tend to only work effectively up to about F5.6, any smaller, and there's not enough light for the AF system to work effectively.
He's correct. I use the matching Sigma 1.4x TC and have gotten some excellent images.

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