Sigma 120-300 OS caf, which converter?

Big Andy · 4 Sep 2011

I have now ordered the above lens and I'm sat here chewing my nails waiting for delivery. So to keep me occupied and semi sane I've decided to look into getting a 1.4x and 2x converter to go with it.
I was wondering if any of you have experience of the different brands available. The body to be used with the lens is the Canon 50d and the subject will be birds/nature. I know the general opinion is to use OEM kit for best results but as the lens is not OEM is there any advantage to getting Canon converters or would Kenko, or Sigma like the lens be just as good, and save a few pennies as well.
Thanks for looking and any input appreciated.

markyboy.1967 · 4 Sep 2011

I use the non OS version of the Sigma 120-300 and use a Sigma 1.4 tc on it--have a look at a few of my threads or on flickr for images with this combo ( 1.4tc doesnt get taken off at all )

Big Andy · 4 Sep 2011

So the pictures in this thread http://www.talkphotography.co.uk/forums/showthread.php?t=348961 are taken on the non OS 120-300? I've got to admit they look nice and sharp, the exif says taken at 320mm so I guess these are taken with the converter attached. I would love to get some images like when it arrives, well captured Mark. :clap:

neil_g · 4 Sep 2011

I'd have to agree the sigma 1.4x works very well on the 120-300 non-OS I have. No noticeable AF slowdown and IQ stays very good.

D3S · 5 Sep 2011

Another 'agree' for the 1.4x on the non-OS; the 2x seems to be generally difficult to work with to achieve decent shots. Enjoy the new lens!

DemiLion · 5 Sep 2011

There are a couple of differing opinions on this page:

http://photography-on-the.net/forum/showthread.php?t=934592&page=80

Personally I'd go for the Canon x2, and have done with the x1.4II.

markyboy.1967 · 5 Sep 2011

Big Andy said:
So the pictures in this thread http://www.talkphotography.co.uk/forums/showthread.php?t=348961 are taken on the non OS 120-300? I've got to admit they look nice and sharp, the exif says taken at 320mm so I guess these are taken with the converter attached. I would love to get some images like when it arrives, well captured Mark.

Yip all those pics were with that combo and 75% of my wildlife stuff on flickr as well.

Big Andy · 5 Sep 2011

Thanks all for your input, and Mark there's loads of info in that link including from yourself and Micoli I see.

Buggerlugs · 5 Sep 2011

I have both the Kenko 1.4x and 2x Pro DGX, both work pretty good with the 1.4x giving the better results of the 2 for obvious reasons, BUT....both have a tendency to cause overexposure by up to 2 stops in mid-low quality lighting, good light rarely causes a problem, I believe this is a well documented quirk when using these TC's especially on a 7D This is something you have to be wary of and make a test shot or 2 and then underexpose as necessary. The Sigma 1.4 EX DG I also have never does this and for this reason I now have a Sigma 2x EX DG winging it's way to me this week. HTH.

The lenses I have tested the Kenko's with:

Sigma 50-150 EX DC f2.8 Mk1
Sigma 70-200 EX DG OS f2.8
Sigma 100-300mm f4 EX DG
Canon 400mm f5.6L