lens focus failure?

[Lisa Nikodym]

Question for you all...
I usually use the Nikon 18-200mm VR DX lens, on a D300 body or an IR-converted D200 body.  On the last two occasions I've used it, it has been intermittently refusing to take a photo.  It seems to work OK when I have it set to manual focus, so I presume that something's flaky with the autofocus.  It must be the lens, because it has this problem on both bodies.  The problem is very intermittent - it will take a photo OK, then (for example) I'll tweak the exposure compensation, and then it stops working for awhile; I push the shutter button, and nothing will happen.  No useful info in the viewfinderf.
I looked at the contacts on the lens, and don't see any obvious problems,
Is this a failure mode that anyone here has experienced?  Is it something that can be *reliably* fixed?  Or is it time for a new lens?

Thanks,
Lisa

[fredjeang]

Question for you all...
I usually use the Nikon 18-200mm VR DX lens, on a D300 body or an IR-converted D200 body.  On the last two occasions I've used it, it has been intermittently refusing to take a photo.  It seems to work OK when I have it set to manual focus, so I presume that something's flaky with the autofocus.  It must be the lens, because it has this problem on both bodies.  The problem is very intermittent - it will take a photo OK, then (for example) I'll tweak the exposure compensation, and then it stops working for awhile; I push the shutter button, and nothing will happen.  No useful info in the viewfinderf.
I looked at the contacts on the lens, and don't see any obvious problems,
Is this a failure mode that anyone here has experienced?  Is it something that can be *reliably* fixed?  Or is it time for a new lens?

Thanks,
Lisa

Hi Lisa.
Well, my answer is NOT scientifical, and it is more like a grandmother remedy. But the same thing happened to me (in a different brand) and I could fix it.
So I give you the trick, thinking that it will probably not work, but who knows...
I just used a screwdriver and carrefuly thightened the 4 screws in the optic mount that with the time had moved. It just worked again.
You have nothing to loose to try it.
Just need a jeweler screewdriver and that's it.

Regards,

Fred.

[Lisa Nikodym]

It worked, Fred!  When I took a closer look at the lens, I noticed the screws on the mount were very loose.  I tightened them, and it's working fine now.

You have saved me the price of a new lens.  It is much appreciated!

Muchas gracias,
Lisa

[Eric Myrvaagnes]

That's great news! 

Now I can breathe easy waiting for your next portfolio.   

Eric

[Rob C]

It worked, Fred!  When I took a closer look at the lens, I noticed the screws on the mount were very loose.  I tightened them, and it's working fine now.

You have saved me the price of a new lens.  It is much appreciated!

Muchas gracias,
Lisa

Lisa, would you expect less from a lover of Jurançon wines?

;-)

Rob C

[fredjeang]

It worked, Fred!  When I took a closer look at the lens, I noticed the screws on the mount were very loose.  I tightened them, and it's working fine now.

You have saved me the price of a new lens.  It is much appreciated!

Muchas gracias,
Lisa

What a great news Lisa!
We can all drink to your successful repair with Jurançon wine  salud Rob !
(actually, these jeweler screwdrivers are one of the very best to have in one's home)

Regards,

Fred.

[Lisa Nikodym]

What a great news Lisa!
We can all drink to your successful repair with Jurançon wine  salud Rob !
(actually, these jeweler screwdrivers are one of the very best to have in one's home)

Alas, I cannot drink alcohol because of stomach problems, but I'll be happy to raise my next glass of fresh orange juice to you, Fred!     You haven't been here on LL very long, but I have already learned that your posts are some of the most useful ones here.

Don't worry, Eric, I resorted to using manual focus whenever the lens flaked out.  Now if I can just find time to process the photos from China last December, from Yosemite Valley in January, and from my weekend trip to the Mendocino coast...  

Lisa

[fredjeang]

Thanks for your kind words Lisa.

IMPORTANT PRECISION

I totally forgotten an important precision.

When that happened to me, I tightened the screws like crazy in order to assure it won't happen again.
That had the effect to compress the all lens structure and guess what? I lost the infinity focus   (and all an afternoon session...)
So I did it again with normal force and everything was back in action.
In fact, these lens are precision mechanical and delicates.
So it is: the screws have to be perfectly tightened but not forced at all.

Check your infinity focus just in case.

Best regards,

Fred.

[Eric Myrvaagnes]

Well go ahead and process! No need to waste time eating and sleeping.    

Eric

[ErikKaffehr]

;-)

What a great news Lisa!
We can all drink to your successful repair with Jurançon wine  salud Rob !
(actually, these jeweler screwdrivers are one of the very best to have in one's home)

Regards,

Fred.

[Lisa Nikodym]

Thanks for the warning, Fred.  I tested it in manual focus mode, and infinity focus is way off.  I sent an email to Nikon service to see if they can adjust the screws (and anything else loose) back to factory specifications and how much it would cost, and I am waiting for an answer.  If it's not much, I'll have them do it.  If there's a problem with that, then I guess I'll just iterate (loosen screws, take a photo, repeat until in focus) myself...

Lisa

[fredjeang]

Thanks for the warning, Fred.  I tested it in manual focus mode, and infinity focus is way off.  I sent an email to Nikon service to see if they can adjust the screws (and anything else loose) back to factory specifications and how much it would cost, and I am waiting for an answer.  If it's not much, I'll have them do it.  If there's a problem with that, then I guess I'll just iterate (loosen screws, take a photo, repeat until in focus) myself...

Lisa

I'm really sorry Lisa. It did worked so well first. I guess you will find the solution, it did happened to me, I had exactly the same problem with another brand (it is like brands talk to each others...) and finaly found the point. It looks I agree like DIY but now works perfectly. I just hope that the fact that the lens has been loosen for a while, more internal disadjustments would have happened but it should not.
Your idea to bring it to Nikon is probably the safest if price is ok, but do not stop to try at home before, I'm sure you will find it.
I know you will find it before send it to Nikon!
Best luck Lisa.

Fred.

[Lisa Nikodym]

No need to apologize, Fred.  Autofocus wasn't working at all before I tried your fix; since I usually use autofocus, the important thing is that it is working now, so your help was very useful.  Getting infinity focus back where it should be would be good, but not absolutely necessary.

Lisa