The Canon EF 70-300mm f/4-5.6 IS USM Lens is not parfocal - you need to refocus if you change the focal length. This is reflected in the new lenses Canon has introduced. Since 1999 (when Canon refreshed its Super Telephoto lens line), zoom lenses have...

Reflected in the new lenses Canon has introduced. Since 1999 (when Canon refreshed its Super Telephoto lens line), zoom lenses have been introduced much more frequently than fixed focal length lenses. performance of the Canon EF 70-300mm f/4-5.6 USM IS...

My 1st generation IS equipped Canon 28-135 IS. I have NEVER used the panning mode for IS so cannot comment on it's performance. Plus, the wide end of the aperature (f4) is insufficient to deliver that beautiful out of focus background... as the faster...

Of 1.6x, such as the Canon EOS 400D, it provides a narrower field of view, equivalent to an 80mm lens mounted on a 35mm frame body. With a 1.3x body such as the Canon EOS-1D Mark III It provides a less narrow field of view, equivalent to an 65mm lens...