Ống kính máy ảnh Canon EF-S 17-85mm f4-5.6 IS

The Canon EF-S 17-85mm f/4-5.6 IS USM Lens combines a very useful zoom range with image stabilization in a light and well-performing package.
 
Keep in mind that the Canon EF-S 17-85mm f/4-5.6 IS USM Lens is an "EF-S" lens and only works on EF-S compatible Canon EOS bodies such as the **D and Digital Rebel / ***D Series. EF-S is Canon's moniker for Short Back Focus. The distance between the film (sensor) plane and the rear of the lens is shorter than in an EF lens. Many question the longevity of this standard. My expectation is that it will be around for a long time - easily long enough for most people to get their desired value from a lens.
 
There also seems to be confusion about how the 1.6x Field of View Crop Factor (FOVCF) relates to EF-S lens framing. The answer is that you still need to apply the "focal length multiplier" to get the conventional 35mm equivalent field of view. The focal length is based on physical design of the optics. Yes, even though the lens is designed for 1.6x FOVCF digital bodies, the framing is still equivalent to a longer focal length lens on a full frame body.