This is a super telephoto lens with a focal length of 600mm telephoto and a 4x zoom ratio. This is the first SLR camera zoom lens in the world to use an inner focusing system for focal adjustments, making this super telephoto while keeping the overall lens structure compact.

Despite being a super telephoto zoom lens, it boasts excellent operability such as zooming and focusing performed using a single knob, a handle as the role of focusing distant objects while also being useful for handling, and a one-touch revolving mechanism.

With regard to optical performance, an original positioning of the optical system and the effective use of UD glass lens element with low dispersion and a low refractive index reduce the size of the optical system while compensating for various aberrations, allowing sharp images with high-contrast to be obtained at all focal lengths.