I recently found that the focus on my D7000 is deteroiting. I noticed today when I went for a hike to take some pictures that it stopped focussing completely > 150mm.. When I bring it closer to the 18-200 it focusses and put the focus points correctly, but farther away it fails! Is it the camera or the lens? Thanks!
Actually, my friend was with me and with a D90 and the a 18-200 and it focused spot on. I also noticed that moving the focus ring on my lens did not focus on the scene at all, it was blurred and out of focus and the same on his d90 focused sharply a little less than infinity.
After this thread, I visited my friends house, swapped out the lens and it does the same thing on his camera, i.e. it autofocuses on near things, but fails to focus on anything at infinity. Putting his lens on my D7000 works like a charm.
It kind of does not make sense to me, why the AF would fail to focus at infinity though..
Mon 30-May-11 06:56 PM | edited Tue 31-May-11 09:52 AM by egmonster
This is apparently a fairly common fault on the 18-200mm. Do you regularly install and remove filters? Often this fault can be traced to a loose front element. I had a 18-200 that did the same thing. Tightened up the front retaining ring and it was fine. Here, check this:
I had the same problem with no focus at 200mm for my NIKKOR18-200VR. As I found on this forum, the problem was caused by a loose front glass, probably caused by unscrewing a filter, which was turned on to strongly. Using the 2 inserts, on the front lens I was able to repair it.
That's great to know. Thanks for the tip. I do agree with Brian earlier in this thread that the contrast and amount of available light has a large effect on this "not very fast lens". I find it great for most of my landscape needs. I found it very frustrating when I couldn't get the autofocus dot to illminate, so I just grab the barrel and manually focus.