There are good number of lenses in 18-200 focal length range from the brand manufacturers and subsidiary companies....The lens (28-300 in 35mm) is an all purpose utility lens covering from wide angle to telephoto....Wide good for scenery, landscapes, large groups...Tele range is good for sports and distant objects, animals, birds that is wildlife photography and moreso candids, which are otherwise unapproachable with wide or normal focal length lenses.
--Sigma's 18-200 f3.5-6.3 II DC OS HSM is an upgraded version of APS-C Lens introduced earlier. The three aspherical glass elements offer correction for distortion. Special low dispersion glass provides optimum colour correction and sharpness. Besides, super multilayer lens coating help reduce flare and ghosting thus providing high image quality throughout its zoom range. Optical stabilization reduces risk of shaky pictures.....The lens come in 18 elements in 13 groups. The focusing is as close as 17 inches in entire zooming range, having a maximum magnification of 1:3.8. The internal focusing system keeps the outer structure intact and makes it easier to use polarising filters...The flower design lenshood keeps the outer flares away while shooting in sunlight.. ..There is automatic panning detection.The filter size is 72mm. The lens weigh 600gms and have a length of 3.1x3.5 inch....shorter to hold in the palm easily......As I experienced many photographers have shaky hands, getting the pictures blurred, but I prefer a good weight in camera and lens to help squeeze the shutter release getting sharp pictures in slow shutter speeds......However, presently the lens is available in Nikon, Canon and Sigma mounts......Just try in a camera shop and instantly view the results on the LCD panel and PC or laptop before going for a final buy.
The Amazon says the price nearly $500, well within the pocket to enjoy the alround photography?