Sigma 1.4X APO Tele Converter for Nikon-AF Camera.

Rating:
Summary: Excellent converter.
Review: 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.

Rating:
Summary: Excellent converter.
Review: 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.

Rating:
Summary: Excellent Teleconverter
Review: 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.