With the Image Stabilizer turned on, it is possible to obtain sharp pictures in dim lighting without using flash or a tripod. With the second generation of Image stabilization, it is reported to be possible to hand-hold the 28-135mm IS lens at 2 stops lower at the telephoto range and 1.5 stops at the wide angle range.
This lens features a ring-type USM that drives an internal lens group for swift, silent autofocus and allows full-time manual focusing (the ability to adjust the focus without disengaging the AF mode). A six-blade diaphragm is used. Closest focusing distance is 20 in. (50cm).
The Canon EF-S 17-85MM f/4-5.6 USM gives a similar field of view on APS-C digital cameras.
While the 28-135 has been the usual 'upgrade' lens replacing a kit lens e.g. EF-S 18-55, EF 28-80, Canon has not marketed an equivalent of an 'all-purpose' lens similar in performance to rival Nikon's 18-200 VR for their EOS digital cameras, leaving the 28-135 as an ideal upgrade. The reason for this - the EOS 5D has a full-frame format similar to a 35mm camera, and most of the professional-grade bodies e.g. EOS 1D, 1Ds use full-frame lenses as opposed to digital-only.
Since August 2007, the 28-135 is included as a kit lens with the Canon EOS 40D.
俺觉得越便宜的越傻