The Sigma 2.0x APO teleconverter lens features a high-performance optical design with five elements in three groups. It is optimized for use with longer telephoto and telezoom lenses, and is ideally suited for use with the 70-200mm f2.8 APO EX HSM zoom lens. This lens provides both normal exposure and autofocus function, while maintaining its high optical performance. Since it uses 10-pin electrical interfaces, there is no loss of autofocusing speed when these teleconverters are used with compatible HSM type lenses. This model is dedicated to Canon AF SLR cameras.
1 Not compatible with all canon lenses
I bought this teleconverter with a 70-300 sigma lenses and it did not mention anywhere (editorial reviews or specifications) that it is compatible with only a specific number of lenses. But the review for the nikon compatible teleconverter it does so. Make sure before you buy it that it will fit your lenses.
2 Nice tele converter.
I bought this teleconverter to supplement a 1.4x converter that I already owned. I wanted to try it out with my Canon 200mm 2.8 lens and compare the results to my 400mm 5.6 lens.
The converter is nice and compact, has a good quality feel to it, and seems to work very well. I shot one roll of film with it so far and was very happy with the results.
Remember that you lose 2 shutter stops when using this converter so it should only be used with a fast lens such as a 2.8 or 3.5 etc.
