Sigma Reviews

Works wonderfully with my Sigma 70-200 f/2.8 HSM. Fast, very sharp. Seems to be very well made. A great addition to any fast Sigma lenses.

I use this converter on my Sigma 70-200 f/2.8 HSM Nikon mount. I used it first last fall at the Petit Le Mans at Road Atlanta and was very impressed with the results. Aperture is reduced to f/4, which is still a bright finder, and autofocus operation is not negatively effected. All electronic functions such as HSM and D coupling still work. Very sharp from my experience.

The Sigma APO teleconverter is a little more than half the price of the Canon teleconverter, and it boasts an APO element to reduce chromatic aberration. I've found this teleconverter to be reasonably sharp, but there is noticeable vignetting when I use it with my Canon 300mm f4. Sigma claims that the teleconverter is designed to be matched with their high-end tlelphoto lenses, and perhaps this is the case. However, I wasn't very satisfied with the performance of this teleconverter.