82mm filter thread diameter

accessories included: bayonet hood (reversible for storage) and a durable, padded nylon lens case

street price; approximately $850

In the Field

As with Canon's USM lenses, focusing performance is fast and silent with both the EOS 1n and Elan 7E. While no side-by-side comparisons with my Canon EF 300/4L were made in terms of autofocus performance, I can say without hesitation that I did not notice any major difference between the two in this regard.

Optically, the Sigma performed extremely well. While there was noticeable barrel distortion at 300mm (far less at 100mm), the lens delivered razor sharp images with accurate color rendition and excellent contrast. Since barrel distortion is only noticeable on straight lines that appear near the edge of the frame, it's essentially a non-issue with most nature and wildlife subjects. With the addition of Sigma's APO 1.4 EX teleconverter, the lens has an effective focal length range of 140mm to 420mm and a constant f/5.6 aperture. With the teleconverter attached, there was a very slight degradation of autofocus performance, as well as a very slight loss of sharpness and contrast, which is expected whenever a teleconverter is used. However, even with the teleconverter attached, image quality remained excellent. The most noticeable effect of the teleconverter (in terms of image quality) was light fall-off in the corners of the frame with the lens wide open at f/5.6, which was substantially reduced by f/8. No light fall-off was apparent when the lens was used alone.

Final Thoughts

The Sigma APO 100-300/4 EX IF HSM is a unique lens...no other manufacturer makes a model like this (Tokina makes a 100-300/4, but without HSM/AF-S/USM focusing). Price wise, the Sigma falls approximately midway between the "consumer" level 100-300 zooms (around $300) and lenses like Canon's 100-400/4.5-5.6 L IS and Nikon's 80-400/4.5-5.6 VR ($1500 plus). From an image quality standpoint, it performs much more like the Canon

100-400 and Nikon 80-400 (the Nikon does not offer internal focusing, internal zooming or AF-S). Interestingly, it matches or outperforms all of these lenses in terms of lens speed (maximum available aperture).

For those nature photographers looking for a high-quality zoom telephoto in this price range with all of the performance and features offered by the Sigma APO 100-300/4 EX IF HSM, there's simply no other game in town...no compromise required.

About the Images

1.Sigma's APO 100-300/4 EX IF HSM telephoto zoom lens.

2.Cottontail Rabbit (Sylvilagus floridanus) - Sigma APO 100-300/4 EX IF HSM, APO teleconverter 1.4x EX, Canon EOS 1n, Bogen 3221 tripod, f/5.6 in AV mode (shutter speed unrecorded), Fuji Provia 100F. Wide open at 5.6, the lens/teleconverter exhibited excellent sharpness and contrast, though light fall-off in the corners was evident.

3.Mullein (Verbascum thapsus) - Sigma APO 100-300/4 EX IF HSM, APO teleconverter 1.4x EX, Canon EOS 1n, Bogen 3221 tripod set up at lens/teleconverter MFD, f/16 (shutter speed unrecorded), Fuji Provia 100F. At f/16, sharpness and contrast remained superb. No light fall-off anywhere in the frame was visible.

JE-NPN 001

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Sigma APO 100-300/4 EX IF HSM specifications Field, Final Thoughts, About the Images