Review: Sigma 50-150mm f/2.8 By
Andrew Alexander (Tuesday, April 22, 2008 - 12:14 EDT)The Sigma 50-150mm ƒ/2.8 II, announced in December 2007, is an update to its previous 50-150mm ƒ/2.8.
It's hard to tell exactly what has been updated: comparing the specifications of the two lenses, they appear almost exactly identical, except version II seems to have shaved off 8mm from the overall length. The difference appears to be in the mount options, as Sigma has made HSM-style versions available for the previously unsupported Pentax and Sony lens mounts. This is good and bad news: while the lens will mount on those bodies, if the body only supports mechanical (screw-driven) style focusing, autofocus will be unavailable. Newer Pentax and Sony bodies will support the HSM standard.
The 50-150mm ƒ/2.8 was and remains a ''designed-for-digital'' lens, with an imaging circle that only covers the APS-C sensor. In this capacity it will provide a field of view equivalent to 75-225mm on a Nikon, Pentax or Sony body, and 80-240mm on a Canon body. Technically, the lens will mount on a film or full-frame body, but circular vignetting will be visible from 50-100mm, and extreme corner darkening is visible from 100-150mm. As well, the lens doesn't have an aperture ring, meaning your film body will have to be able to set lens apertures to operate the lens completely.
The lens takes 67mm filters, comes with a standard round lens hood, and is available now for around $700.
Review: Sigma 50-150mm f/2.8
