Hi friends, I have Nikons d7200 and d500 and my favorite walk around lens is the Nikkor 18-200mm. Recently it began slipping. I now use a band on it, but I just don't feel the photos are as sharp arls they once were. I know with a long zoom sharpness is often compromised, and I have several other lenses that do an excellent job. But as an almost 72 yr old woman, although spry enough, sometimes I just want to grab one lens for a long hike. I'm looking between Nikkor, Tamron, and Sigma. I want new, as I don't want to deal with slipping again any time soon. I'm looking at 18mm-300mm, or even 400mm is quality isn't terribly compromised. And suggestions from personal experience? Thank you!!