Win a Pentax Limited Lens: Raffle Now Live!

Sigym · 11-13-2009, 04:14 PM

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.

pcarfan · 11-13-2009, 04:32 PM

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.

GaryH · 11-13-2009, 06:42 PM

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.

pcarfan · 11-13-2009, 07:15 PM

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.

Fl_Gulfer · 11-13-2009, 07:58 PM

I also use the Tamron 1.4 with my 100-300 and like it alot.

davidvcd · 11-14-2009, 02:34 AM

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.

pop4 · 11-14-2009, 05:30 AM

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.

**wtlwdwgn** · 11-14-2009, 11:37 AM

Originally posted by pop4

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.

11-13-2009, 04:14 PM	#1
Sigym Inactive Account Join Date: Nov 2009 Location: Texas Posts: 2	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.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Tamron adaptall 300/2.8 or Sigma 100-300/4	pinholecam	Pentax SLR Lens Discussion	10	11-07-2009 05:52 AM
Tamron 300/2.8, Sigma 100-300 F4, 1.7 AF TC images: A link to the DPR froum.	pcarfan	Pentax SLR Lens Discussion	0	02-07-2009 08:48 PM
Wildlife & sports tele: DA*300 vs Sigma 100-300 f4	dspdx	Pentax SLR Lens Discussion	4	08-28-2008 09:27 PM
Sigma 100-300 APO vs New Pentax 300	dylansalt	Pentax SLR Lens Discussion	10	07-24-2008 05:44 AM
Sigma 100-300 f4 vs Sigma 50-500 Bigma	smcclelland	Pentax SLR Lens Discussion	5	08-17-2007 11:12 AM

11-13-2009, 04:32 PM	#2
pcarfan Veteran Member Join Date: Sep 2007 Location: Dayton, Ohio Photos: Gallery \| Albums Posts: 2,978	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
GaryH Site Supporter Join Date: Oct 2009 Location: Philadelphia, Pa Photos: Gallery Posts: 764	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
pcarfan Veteran Member Join Date: Sep 2007 Location: Dayton, Ohio Photos: Gallery \| Albums Posts: 2,978	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
Fl_Gulfer Veteran Member Join Date: Jul 2007 Location: Florida Gulfer Photos: Albums Posts: 3,054	I also use the Tamron 1.4 with my 100-300 and like it alot.

11-14-2009, 02:34 AM	#6
davidvcd Senior Member Join Date: Aug 2009 Location: NorthernVA , USA / Grenoble, FRANCE Posts: 148	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
pop4 Veteran Member Join Date: Aug 2007 Location: YMML Photos: Gallery Posts: 1,879	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
wtlwdwgn Site Supporter Join Date: Jan 2007 Location: Billings, MT Photos: Gallery \| Albums Posts: 13,853	Originally posted by pop4 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.

Sigma 100-300 f/4 EX DG

Win a Pentax Limited Lens: Raffle Now Live!