Canon EF-S 17-85mm lens
|This article does not cite any references or sources. (December 2009)|
|EF-S 17–85mm f/4-5.6 IS USM|
|Short back focus:||Yes|
|Focal length (35mm equiv.):||27-136mm|
|Frame coverage:||APS-C 1.6x|
|Aperture (max/min):||f/4.0–5.6 / f/22-32|
|Construction:||12 groups / 17 elements|
|# Diaphragm blades:||6|
|Close focus distance:||0.35 m (1.1 ft)|
|Max. magnification:||0.20x @ 85mm|
|Max. diameter:||78.5 mm (3.1 in)|
|Max. length:||92 mm (3.6 in)|
|Weight:||475 g (1.1 lb)|
|Filter diameter:||67 mm|
|Case:||LP1116 Soft Case|
|Angle of view|
|Horizontal:||68°40' – 15°25'|
|Vertical:||48° – 10°25'|
|Diagonal:||78°30' – 18°25'|
The Canon EF-S 17–85mm f/4-5.6 IS USM is a standard zoom lens for Canon digital single-lens reflex cameras with an EF-S lens mount. The EF-S designation means it can only be used on EOS cameras with an APS-C sensor released after 2003. The field of view has a 35 mm equivalent focal length of 27.2–136mm, and it is roughly equivalent to the Canon EF 28-135mm lens on a 35mm film SLR. Despite the word "macro" being present on the lens body (as visible in the infobox image), this lens is not capable of true 1:1 macro photography.
The 17-85mm is bundled as a kit lens with the EOS 30D, EOS 40D, EOS 50D and EOS 60D. It was also packaged with the EOS 400D (known as the Digital Rebel XTi in North America) as an alternate to the EF-S 18-55mm (typically labeled as the "400D enthusiast's kit").
Similar lenses 
The EF–S 17–85mm is a step up in build quality and in focal range compared to the EF-S 18-55mm lens. Its image quality is higher than the original and the Mark II versions of the 18-55mm lens. It is slower and has lower image and build quality compared to the EF-S 17-55mm lens, although it is cheaper and has a longer focal range.
The closest lens to the 17-85mm in the standard EF lens range is the EF 28-135mm lens, which has the equivalent range on a full-frame sensor, similar image quality and image stabilization.
Performance Issues 
A common flaw with the EF-S 17-85mm is that after several years of use the diaphragm flex cable can tear or sever within the lens. When this happens the diaphragm will become inoperable and the lens will only work at maximum aperture (f/4-5.6). If the user tries to operate the lens at a non-maximum aperture (i.e. an aperture where the diaphragm is used to stop down the lens) the camera will display "Err-01" and an instruction for the user to clean the lens contacts. If cleaning the lens contacts does not fix the problem then there is a high probability that the flex cable has indeed been severed. The lens can be sent into Canon for repairs which will cost ~$200. Or the user may try to replace the flex cable themselves. This will require disassembling the entire lens and soldering the new cable into position.