The Vivitar 1.4x Auto Focus Tele Converter for Sony is an easy way to noticeably extend the reach (focal length) of compatible lenses. The 1.4x Tele Converter can be mounted between select lenses and the camera body to increase the focal length by the power of 1.4x. The new multi layer coating reduces flare and ghost, which is a common problem with digital cameras.
They also offer maximum photography magnification by 1.4 x, without any variation in the minimum focusing distance. Compact and lightweight, these teleconverters convert your lenses into longer focal-length lenses, so you don't have to do a lot of unnecessary footwork.
Reviewed by 2 customers
A little disappointed because it doesn't work with my main lenses: DA* 16-50 and Sigma 70-200 2.8 (HSM lenses just keep hunting and flashing) Somebody said don't use tele converter with wide angle lenses, but the auto focus works fine with the DA 18-250mm and FA 24-90mm and don't know why It doesn't work with my FA-100 2.8 (?!)
Finally. It took a very old friend "Vivitar" two tries, but this on really works. I do not write reviews but thought this one needed writing. Less than $100.00, great value. Tight fit even on my very used K10d. Two Tamron and one Pentax lens. A little slow finding infinity and focusing first start, Fine after that.