I bought one of these to use next year on a Euro rivers cruise. I've just compared it in focus to a second generation 43-86 Nikkor. When I focus the 43-86 using the green dot, If I am careful, the green dot remains constant throughout the zoom range. And this lens is a two touch zoom (aperture one control, focus and zoom the other) There is decided focus shift with the 28-85, no matter how careful I am, and this lens, with its extra control, should be easier to maintain focus. I wrote down the figures at about an eight feet distance from camera to subject, checking and re-checking. I've tossed the piece of note paper away, so I will have to do it again, but it was quite noticeable. I'll get back to you on this when i've sorted the kitchen faucet change, which is more pressing, and which has created a huge mess in the kitchen.