EF-S 18-55mm f3.5-5.6
The EOS 300D features a new dual lens mount. This accepts all in the EF, TS and MP lenses in the EOS system (over 100 if you include the discontinued lenses). It also takes the new EF-S 18-55mm f3.5-5.6 lens. However, the new lens will not fit other EOS cameras. A rubber ring at the rear of the EF-S lens prevents any damage if you try to mount the lens on a camera other than the EOS 300D.
The EF-S 18-55mm lens will not be sold separately and will only be available when purchased together with the EOS 300D.
The more compact sensor size of the EOS 300D means the camera’s reflex mirror can also be smaller, making it possible to bring the back of the lens closer to the image sensor. The ‘S’ in the EF-S nomenclature stands for ‘short back focus’, which describes this new system.
The EOS 300D features an APS-C sized sensor. A lens used with this camera has a narrower angle-of-view than when used with a 35mm film camera, giving a 1.6x magnification effect over 35mm film format. The new lens gives a field-of-view on the EOS 300D equivalent to a 28-90mm zoom on a 35mm camera.
Manufacturing costs associated with such a wide-angle zoom lens would normally be very high. The ‘short back focus’ system of the EOS 300D, however, has allowed Canon’s design engineers to develop a remarkably low weight, shot length lens that retains all the high quality hallmarks of the EF range. The result is an opportunity for EOS 300D users to work with a lens that would normally carry a prohibitively expensive price tag.
By optimising the EF-S 18-55mm f3.5-5.6 lens coatings, Canon’s engineers have effectively minimised the chance of flare and ghosting which are more prone to occur with digital cameras than with film cameras. The coatings reduce reflections off the rear of the lens to deliver crisp, undistorted digital images.
The drive pattern of the lens has been tailored to specifically match that of the EOS 300D, for quiet, precise and fast autofocus. A minimum focusing distance of just 0.28m is available at all focal lengths through the zoom range.
EOS magazine, September 2003, page 59