The following information was included in the Canon EOS Rebel XSi / 450D Press Release.
EF-S 55-250mm f/4-5.6 IS Lens
Like the standard kit lens, the optional Canon EF-S 55-250mm f/4-5.6 IS Lens offers users of Canon EOS Digital SLRs with APS-C type CMOS sensors an affordable, lightweight, high-performance lens with tremendous range and flexibility. Given the 1.6x conversion factor inherent in the APS-C sized sensor, the high zoom ratio of this EF-S 55-250mm lens actually achieves the equivalent focal length of 88-400mm (in 35mm format).
Canon's true optical, lens shift image stabilizer offers users an equivalent shutter speed that is approximately 4 settings faster, making hand-held lower light or long zoom photos easier to capture without blurring. What's more, the lens can automatically distinguish between normal shooting and panning shots and select the optimum Image Stabilizer mode for each.
In stores now, both the EF-S 18-55mm f/3.5-5.6 IS and the EF-S 55-250mm f/4-5.6 IS zoom lenses are manufactured by Canon specifically for the EOS Rebel XSi,
EOS 40D and every other EOS SLR that takes EF-S lenses including earlier Digital Rebel cameras and the EOS 20D, EOS 20Da, and EOS 30D models.
Though standard in the EOS Rebel XSi kit, the EF-S 18-55mm f/3.5-5.6 IS lens is also available as a stand alone purchase and carries an estimated retail price of $199.99.
The optional EF-S 55-250mm f/4-5.6 IS lens is available at an estimated retail price of $299.99.
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