Has anyone seen this before?
Set the focus to infinity and initiate auto focus = image 1
Set focus to minimum and initiate auto focus = image 2
image 3 is the same as 2, but stopped down from 2.8 to 4.5
Also, does the sharpness at 2.8 look normal for this lens (with correct focus)?
I get the same thing on the D200 and the D1H, so it is not the camera. It appears to be a fixed error as far as I can tell, since the error is less noticeable as you move away. It appears to be off by 1.5 ft at 7 ft, 15 ft and infinity. I normally do not use it for close work so have not noticed this before.
I took the usual precautions to prevent vibration (lots of light, high shutter speed, cable release, tripod, exposure delay mode). I also checked it with a normal focus test target. Starting at close focus, it is dead on.
I assume it needs to go to Nikon but am wondering if anyone has had similar troubles.
Edited by mhayes5254 on May 11, 2008 at 04:33 PM GMT
I've never seen this before. I would assume there is something wrong with your lens.
But before you draw conclusions, you could check VR (it could be that there is an interference between AF and VR during a fraction of a second, making the behaviour different between "past" and "closer" focus, since the time to focus is different)
VR needs to stabilize (needs a few tenths of a second)
Also switch off VR if you do your testing on a tripod.
Guy,
I went to check the effect of the VR on/off and, without changing anything, it worked fine (it was off).
I discovered the focus limit switch was on (2.5m-infinity) and this time I was just past 2.5 m.
It seems that if you are within the limit, it will focus out to the target correctly, but of course will not focus in to the same point. Makes perfect sense, although I would not have expected it to work within 2.5 m in either case . In that case I would have thought to check the limit switch.
I had called Nikon and described the behavior and they just said to send it in. I new it was very strange behavior, which is why I posted it here. Thanks for the suggestion. Although I was not the VR, it caused me to stumble on the solution
mhayes5254 wrote:
Guy,
I went to check the effect of the VR on/off and, without changing anything, it worked fine (it was off).
I discovered the focus limit switch was on (2.5m-infinity) and this time I was just past 2.5 m.
It seems that if you are within the limit, it will focus out to the target correctly, but of course will not focus in to the same point. Makes perfect sense, although I would not have expected it to work within 2.5 m in either case . In that case I would have thought to check the limit switch.
I had called Nikon and described the behavior and they just said to send it in. I new it was very strange behavior, which is why I posted it here. Thanks for the suggestion. Although I was not the VR, it caused me to stumble on the solution ...Show more →
I did the same thing this week! Was agrivated that the lens would not focus right. Fortunately I checked my switches and found the issue. Glad your copy is fine.
hmmm this looks like my version of the 70-200VR... when i used it, it also released a lemon scent. that scent was the only thing i liked about that lens. i never took the effort to get it fixed.
. In that case I would have thought to check the limit switch.
I did the same thing this week! Was agrivated that the lens would not focus right. Fortunately I checked my switches and found the issue. Glad your copy is fine.