This is aspherical zoom lens is a 2 in 1 zoom lens taking care of 28-70mm and 70-210mm zoom lens so no more lens changing hassles.The results from this lens has come out very well and the crispness, clarity, exposure and sharpness are quite satisfying.It's quite compact and lightweight but not as light as the Tamron's 28-200mm. But then I guess weight does add sturdiness and strength to a product.It's got a very good aperture range of 3.5-5.6 for such a huge focal range. The aspherical design has added to it's compactness. Due to the non-rotating filter mount, using of polarizers has become easier.On the downside the depth of field is the only casualty in the mid to tele range compared to smaller range zooms.