Canon has created two new versions of its Image Stabilizer (IS) super-telephoto lens with the EF 600mm f/4L IS II USM and EF 500mm f/4L IS II USM models.

Replacing the current EF 500mm f/4L and EF 600mm f/4L IS lenses, the new models are 18 percent lighter (112.5 ounces) and 27 percent (138.3 ounces), respectively. They have also been fitted with two, lightweight fluorite optical lens elements (the heavier UD glass elements have been removed), which help to minimize chromatic aberration and eliminate color blurring around the edges of the subject.

Image stabilization has also been improved, providing the equivalent shutter speed of approximately four steps faster. With the power focus mode, users can use manual rack focusing by turning a playback ring that is normally used for the focus preset function. Both low-speed and high-speed focus shifting are available.

The Canon EF 500mm f/4L IS II USM lens is expected to be available in May for $9,499, while the EF 600mm f/4L IS II USM lens is expected to be available in June for $11,999.