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I've just noticed a problem with my 70-200 VR.

Sometimes it seems to get stuck at the minimum focus position. Not physically stuck, just can't regain focus.

As far as I know, if the camera can't obtain focus, the lens will cycle through it's focus range and finish up at infinity. Further attempts to focus will cause lense to cycle from infinity to min then back to infinity. right?

My 70-200 stops at the min focus position. When I try to focus again, the focus motor starts a bit and the focus ring moves a fraction but thats all. If I hold the focus ring, it squeeks instead of moving a bit.

Occasionally it comes 'unstuck' and will cycle through focus range.

Any ideas?? Am I off to Lidcombe again??

My 18-70 and sigma 105 seems to focus ok

I've actually noticed the same thing on my 28-70. It's the only lens I have that seems to have this problem. If I turn the camera off and on again it sometimes fixes it. Other times I've had to remove the lens and re-attach to fix it. It may sound silly, but I think it only does it when I have the lens hood attached (which of course is most of the time).

Cheers
John

Tried it on a different body?

Kyle wrote:Tried it on a different body?

No. not yet.

johnd wrote:I've actually noticed the same thing on my 28-70. It's the only lens I have that seems to have this problem. If I turn the camera off and on again it sometimes fixes it. Other times I've had to remove the lens and re-attach to fix it. It may sound silly, but I think it only does it when I have the lens hood attached (which of course is most of the time).

Cheers
John

I'll try those things. Except the lens hood. That's beyond silly.

Do you keep the cpu contacts on both lens and body clean?

When the focus is stuck, can you hear the AF motor trying to do something (quite a faint noise)? I had a problem with my 17-35 where the AF would stop working and I had to manual focus. This now is the case at anything below about 22mm (and manual focus won't focus to infinity )

P

Which body is that lens on?

Are you trying to focus on something with high contrast in good lights or just plain dark objects or the sky?

In what situation it comes back alive and start focusing again?

greencardigan wrote:My 70-200 stops at the min focus position. When I try to focus again, the focus motor starts a bit and the focus ring moves a fraction but thats all. If I hold the focus ring, it squeeks instead of moving a bit.

Any ideas?? Am I off to Lidcombe again??

Do you have focus switch on side of lens at "infinity-2.5m" or at "full'?

I have the exact same issue with mine greencardigan. AF limiter doesn't make a difference, it still does it at large subject-camera distances. I haven't actually bothered doing anything about it though, as it's quite rare for the AF mechanism to lose focus altogether. If it does, I just rotate the focus ring so that the image is close to in-focus again, then it will AF just fine.

I'll be interested to see how you get on at Lidcombe, please let me know.

Kyle wrote:Do you keep the cpu contacts on both lens and body clean?

I'll pretty sure they are clean. Though I will check again.

Reschsmooth wrote:When the focus is stuck, can you hear the AF motor trying to do something (quite a faint noise)? I had a problem with my 17-35 where the AF would stop working and I had to manual focus. This now is the case at anything below about 22mm (and manual focus won't focus to infinity )

Yes, It sounds like it's trying to start focussing.

Yi-P wrote:Which body is that lens on?

Are you trying to focus on something with high contrast in good lights or just plain dark objects or the sky?

In what situation it comes back alive and start focusing again?

D70

I first noticed it taking some pics in my yard of a bird in a tree. Lowish light be should have been adequate for camera to focus properly. But the testing i've done was indoors on a white wall.

Seems to comes back alive at random. Usually after a few half presses.

cricketfan wrote:Do you have focus switch on side of lens at "infinity-2.5m" or at "full'?

Full. I haven't really tested it with the limit switch on.

MCWB wrote:I have the exact same issue with mine greencardigan. AF limiter doesn't make a difference, it still does it at large subject-camera distances. I haven't actually bothered doing anything about it though, as it's quite rare for the AF mechanism to lose focus altogether. If it does, I just rotate the focus ring so that the image is close to in-focus again, then it will AF just fine.

I'll be interested to see how you get on at Lidcombe, please let me know.

Not sure if I'll do anything about it yet. It's annoying but I can probably live with it.

Thanks everyone for the help/suggestions.

my 80-200 2.8 is doing the same thing , and is off to Andersons for a check up today It's not a vr, but won't focus on anything too 'close' and has a wonderful squeeling sound while it whirs away

I'll let you know what happens

I had another play with my 28-70 over the weekend. It misbehaves on both camera bodies. The contacts are clean. It seems to focus OK on the first 20-30 shots, then the problem kicks in. Maybe it's an overheating problem (in Tasmania this time of year, maybe not). You can hear the little focussing motor trying to do it's thing. Occassionally you hear a clunk or two and sometimes it will acquire focus. It is definately not hunting, just not moving. Almost like the focussing motor is trying to drive it but without success. A thought I had was could I have picked up any dust or grit inside the lens that could be jamming things? It hasn't been in a gritty or sandy environment to my knowledge, but could a small particle inside the lens be causing the problem. It's interesting that it's happening on a number of diferent Nikon top quality lenses.

Cheers
John

I checked my contacts too. Clean.

The problem with my lens disappears when the focus limiter is on.

I finally got around to taking my 70-200VR to get checked out.

The quote for the repair is $371. That's less than I was expecting but still not sure if it's worth going ahead with. I can live with the lens how it is but it's quite annoying.

I'd suggest it may be something to do with the D70 and the lens as a combination.

I too had the same problem with my D70 and 70-200VR intermittantly.

Switched to a D200, no more problem and nothing done to the lens.

It might be worth saving the $371 and putting it towards a secondhand D200, I'm sure there will be some bargains available very shortly with the D3 & D300 ready to hit the streets......

Did they tell you what is wrong with the lens or is that price quoted just for a service?

Mine happens on both D70 and D200... not that it bothers me terribly though.

TonyH wrote:Did they tell you what is wrong with the lens or is that price quoted just for a service?

I did talk to someone but he didn't really understand what the problem was. Some circuit board needs replacing + something to do with brushes? and contacts.

I'm going to ring again today and see if i can talk to the guy who pulled it apart.

johnd wrote:I've actually noticed the same thing on my 28-70. It's the only lens I have that seems to have this problem. If I turn the camera off and on again it sometimes fixes it. Other times I've had to remove the lens and re-attach to fix it. It may sound silly, but I think it only does it when I have the lens hood attached (which of course is most of the time).

Cheers
John

If you want to test this - we could always catch up sometime? I now have a 28-70 as well as the D200. Haven't seen any problems as yet with either the lens.

If it is the lens hood, sounds almost like a mount/contact issue.

I got my 70-200VR back this morning after nearly 3 months at Nikon.

Cost me $360 to get the relay PCB and 2 brushes? replaced. Most of the cost was for labour. The repair sheet says they had to completely dismantle the lens.

I'm glad your lens is working properly as it should now.

Have you tried accuracy of focus? Make sure it has no front/back focus issues within your repair warranty.

Yes, I gave it a quick test. It seems to focus accurately with with my recently adjusted D70.