Diagnostics on an old lens?

[mimstrel]

I have an old Vivitar 200mm f3.5 Nikon non-AI mount prime that I got off eBay almost two years ago.
I've used and loved it... and then, it stopped focusing. Or rather, the focus no longer changes. It's an old lens, obviously, but cosmetically, it's in great shape. No indication that it has ever been dropped or abused, and I have certainly never dropped or abused it. My laptop gets more abuse than my glass!

Does anybody know what might have gone wrong? Is it just a case of some gear inside getting worn out? Can that be fixed? Is it WORTH fixing? Is there some really obvious thing I'm missing? I really can't afford to take it in for repairs or to replace it at the moment, so I'm really hoping it's something really obvious or easily adjusted.

I can post photos of the lens, but like I said, from the outside it looks just fine; I don't think looking at a picture of it will help.

 

[Mike_E]

If you shake does it rattle?

 

[mimstrel]

Very quietly, but yes.

ETA: But my other old lens rattles just the same way, and it works just fine...

 

[spazoid1965]

I have this same lens. Mine works perfecltly. But when I shake mine the slight rattle sound seems to come from the apeture ring area of the lens. Is that where the rattle is in your lens? Or does the sond seem to come from the middle of the lens? I've never taken this style of lens apart before. But they definately aren't worth taking in for repairs. They are just to cheeap on ebay to bother paying for repairs. If you feel brave and have the proper tools try taking it apart. What do you have to lose since it doesn't work anyway.

 

[compur]

I have an old Vivitar 200mm f3.5 Nikon non-AI mount prime that I got off eBay almost two years ago.
I've used and loved it... and then, it stopped focusing. Or rather, the focus no longer changes. It's an old lens, obviously, but cosmetically, it's in great shape. No indication that it has ever been dropped or abused, and I have certainly never dropped or abused it. My laptop gets more abuse than my glass!

Does anybody know what might have gone wrong? Is it just a case of some gear inside getting worn out? Can that be fixed? Is it WORTH fixing? Is there some really obvious thing I'm missing? I really can't afford to take it in for repairs or to replace it at the moment, so I'm really hoping it's something really obvious or easily adjusted.

I can post photos of the lens, but like I said, from the outside it looks just fine; I don't think looking at a picture of it will help.

These Vivitar 200/3.5 lenses are great and they were made with different
cosmetics over the years. Does your lens have a rubber grip on the focus
ring? If so, it's possible the adhesive on the grip has simply dried out so
that when you turn it you're only turning the rubber grip and not the focus
ring beneath it. You should be able to tell by simply gripping the focus ring
more firmly while turning to see if that works. If that's the case it's only a
matter of replacing the glue. Fold back as much of the grip as you can and
apply contact cement. Then wrap with elastic or rubber bands until it sets.

Otherwise, if it's an internal mechanical problem, a repair would likely cost
more than replacing the lens.

 

[Dallmeyer]

I have a Viv 70-200 here that works ok. I shake it and it rattles too. Mine sounds like the spring connecting the actuator lever for the iris.

Mimstrel, when you turn the focussing-ring towards minimum focus, does the lens become physically longer in length?

 

[mimstrel]

Thanks everybody! Sorry it's taken so long to get back to this. It's been a crazy couple of months.

These Vivitar 200/3.5 lenses are great and they were made with different
cosmetics over the years. Does your lens have a rubber grip on the focus
ring? If so, it's possible the adhesive on the grip has simply dried out so
that when you turn it you're only turning the rubber grip and not the focus
ring beneath it. You should be able to tell by simply gripping the focus ring
more firmly while turning to see if that works. If that's the case it's only a
matter of replacing the glue. Fold back as much of the grip as you can and
apply contact cement. Then wrap with elastic or rubber bands until it sets.

Otherwise, if it's an internal mechanical problem, a repair would likely cost
more than replacing the lens.

Nope, there isn't any rubber grip. Darn, that would have been a simple fix!

Mimstrel, when you turn the focussing-ring towards minimum focus, does the lens become physically longer in length?

Not anymore.

I have this same lens. Mine works perfecltly. But when I shake mine the slight rattle sound seems to come from the apeture ring area of the lens. Is that where the rattle is in your lens? Or does the sond seem to come from the middle of the lens? I've never taken this style of lens apart before. But they definately aren't worth taking in for repairs. They are just to cheeap on ebay to bother paying for repairs. If you feel brave and have the proper tools try taking it apart. What do you have to lose since it doesn't work anyway.

The rattle is from the aperture ring area. If I had the tools I would be willing to take it apart - I'm pretty handy and, as you say, what do I have to lose?
I'll do some research and see what it would take to do so. If nothing else, I get an education in how lenses are put together.