Very good value for this purpose all in one ... from wide angle to telephoto in price. Certainly it has not opened as a 5.6 Canon 18/200 or diameter of 72mm as Sygma in 18/200 ... and because it is a 18/270 and that if we loses a little on one side, the other one wins. The pro will say that the dive at some outlets are ... there are disadvantages in all, but here, with this objective, it is an efficient compromise, to make good pictures without being a pro. I did some tests and I find it better than my old Tamron AF 28/200, it must be said that this model is the latest generation with the PZD (powerful and quiet motor for autofocus), it is a little smaller and lighter than its predecessor and not always n''est as stated in the ad ... comes with its "Corolla" by Sun. In short, I'm really happy with my choice and it was not easy. Precision, it is mounted on a Canon 550D.