<p>I have been using a Nikkor 70-200 VR II on a D300 for years now and the warranty of the lens is drawing to a close. (mid-June 2016) – The first two years I felt as if I couldn't take a "non-sharp" picture...it was fantastic...<br> But later on I discovered that it seemed like shooting at the 200 setting would not give the same perfect results as shooting at, say 190mm, or 185...Peculiar I thought and one day I made a very deliberate test, to see if I was imagining or not...<br> I was not, shooting at 185 did produce a picture with higher resolution that if I had shot at 200...clearly, this is not what we want to be the case...<br> So, since I'm in Los Angeles, I took lens to Nikon on Wilshire...<br> After picking up lens, hoping I'd see no such anomalies again, I was disappointed to see that nothing seemed to have changed at all...but Nikon places lens in a plastic bag and affixes a yellow sticker stating that "lens performs in accordance with Nikon specifications"....<br> I took it back...same result..a third time – this time I let Nikon have my camera in order to establish easier what the situation was...that resulted in Nikon asking for hundred of dollars "to service camera"..! – I declined, having had no issues with the camera – and they didn't say what prompted suggested service charge...<br> This third time I had also created a graph showing very clearly what I had experienced, thinking, that would be helpful for them! – I don't believe they did anything at all with the lens...they may have looked at it, seeing no problem, then putting lens in plastic bag, plus affixing the yellow sticker...<br> ...now, Nikon may be right and in fact, I wish they were right – I would rather the lens operates perfectly but has difficulty with the camera's focus assisting abilities – but I want Nikon to PROVE that to me and not just make assertions via yellow stickers...<br> Now, spring of 2016, it's essentially hit or miss with this lens and camera combination...I may get incredibly sharp results or way soft images...(no, I don't have another Nikon to compare with...)<br> As I have searched on the web, I have found that if mirror in camera gets misaligned, it might cause focusing problems...seems logical. And I have searched to see if auto-focus lenses like this one, eventually lose their focusing capabilities, but I haven't found any results or explanations.<br> Now I don't know what to do, except go back a fourth time before warranty runs out...<br> Tests I have done, seem to show that at close range, very close range, focus seems to work well throughout...but at a distance, it will work well, if I'm lucky, between 140-185 or so, but not at the 70-110 range...(or at 200mm)<br> Thoughts...? – ..and thanks for reading my fairly lengthy description...</p>