In locul tau eu as alege Nikon. Fragmentul de jos il gasesti aici :
http://www.kenrockwell.com/nikon/1870.htmPerformance
It's sharp, focuses fast and silently and has instant manual focus override like all AF-s lenses. The distortion is fairly typical: barrel at wide, neutral in the middle and some pincushion at the tele end.
Some people worry too much about sharpness. On a digital camera you get up to a certain spatial frequency and the MTF drops to zero thanks to the antialiasing filter and the CCD layout, thus it's much easier to characterize lenses for digital cameras. Sharpness is easy to get on digital camera lenses and this is as sharp as it can be. Nikon posts the MTF curves at the bottom of this page.
Discount lens makers are trying to scare people into thinking that they just invented magical "digital" lenses in an attempt to make people think that the discount lenses somehow outdo the existing lenses you already own. Nope. Your 15 year old AF lenses are just great on a digital camera.
Film lenses are trickier since the MTF curve extends, albeit at a very low amplitude, to triple digit c/mm. Digital cameras stop at about 30 c/mm.
This lens is completely sharp. Go for it