Do you really need more than 1 lens? Maybe not--this Sigma 50-500mm F/4.5-6.3 APO DG OS HSM Lens for Pentax covers a lot of ground. The 10x zoom can be used on everything from landscape and portrait photos to sports action and wildlife photography. It uses 4 Special Low Dispersion (SLD) glass elements for optimum color correction and sharpness through the entire zoom range, and a Hyper-Sonic Motor (HSM) provides quiet and high-speed auto focusing. The Optical Stabilization (OS) system allows you to use the lens even off a tripod to capture sharp, clear photos. 

This 50-500mm lens is designed for use with Pentax DSLR cameras--with an APS-C-sized sensor, the effective zoom range is approximately 75-750mm in 35mm equivalent. Note: The Pentax mount tele converter cannot be used with this lens.

Note: Pentax mounts do not have an aperture ring--some functions may not work depending on the camera model.

Note: It is not possible to use the AF and the built-in OS function of this lens when attaching it to film SLR cameras as well as Pentax *ist series and K100D.

Note: When using the OS function of a lens with a camera which incorporates a stabilizer unit, please turn the camera's stabilizer unit off.