I was checking the Canon website and found that the EF-S 15-85mm f/3.5-5.6 IS USM lens is a "standard" zoom lens, whereas the EF 17-40mm f/4L USM is described as an "ultra-wide" Zoom.
Is there anything else other than focal length which makes a lens ultra-wide angle or standard zoom?
Answer
The EF-S 15-85 can be used only on APS-C cameras, where it will have an full frame equivalent focal length of 15 * 1.6 to 85 * 1.6 = 24-136mm. As such, it's approximately equivalent to a "normal" zoom on a full frame camera.
The EF 17-40 when mounted on a full frame camera has the stated focal lengths (17-40mm) and is an ultrawide zoom. However, if you mount it on a APS-C camera, its equivalent focal lengths will be 27-64mm and it could be considered to be a normal zoom.
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