Image Stabilizer 
Image Stabilizer (IS) dramatically reduces image blur caused by camera shake. Gyro sensors detect unwanted vibrations, triggering the corresponding movement of a correcting lens group perpendicular to the optical axis. This alters the light path, returning the image to its correct position on the sensor or film plane.

The 3-stop advantage means that photographers normally shooting a 105mm lens handheld at 1/125 second can obtain a shake free result with a shutter speed as low as 1/15 second, for vastly extended options in low light conditions.

Superb autofocus 
The ring-type USM motor found in the EF 24-105mm f4L IS USM employs ultra-sonic frequency vibrations to drive autofocus with unrivalled speed and near-silent operation. A powerful CPU and improved AF algorithm contribute to speed performance. Good holding torque stops the lens with precision and accuracy, the instant it arrives at the correct focus point and without overshoot. Photographers can choose manual focus instantly and at any time simply by moving the manual focus ring without first having to switch out of autofocus mode.

Constant f4 aperture from 24 to 105mm 
The EF 24-105mm f4L IS USM offers the highest possible optical quality with no change in aperture over the full focal range of the lens. This allows photographers to set exposure at the widest aperture and zoom all the way through to 105mm without having to vary the shutter speed. It is the perfect lens for professional photographers looking for a lightweight and extended zoom alternative to its EF 24-70mm f2.8L USM counterpart. The lens employs an almost perfectly circular barrel aperture, helping create attractive, defocused backgrounds.

Image quality 
To limit lens size and improve image clarity over the total image area, an Ultra-Low Dispersion glass (UD) element is used to eliminate the secondary chromatic aberrations that otherwise reduce sharpness and introduce color fringing. Aspherical lens elements correct spherical aberration for crisp, high-contrast, corner-to-corner quality. By optimizing Super Spectra lens coatings and lens element shaping, Canon's engineers have been effective in suppressing flare and ghosting--more prone to occur with digital cameras due to reflection off the image sensor. By increasing light absorption, coatings reduce reflections off lens element surfaces to deliver crisp, undistorted images with natural color balance.

EOS system integration