I've got to admit -- I suspect a design "problem" w/the zoom slipping. I've
got an
absolute >mint< 100-200mm in the shop right now (virtually never used) that
almost
flops when you point it down! Olympus was out of the largest (most friction)
size
rollers the last time we ordered them, so one of my techs took a roller from
another lens and filed and cut it till it fit -- we'll try it for a while to
see if
it's any better over time....
The varying "drag" you feel is normal, too -- the "floating" lens groups move at
different rates as you zoom it, so many zooms will feel varying degrees of
resistance as you move the zoom.
Curtis P. Hedman wrote:
> >Date: Tue, 28 Aug 2001 12:56:24 -0500
> >From: clintonr
> >Subject: Re: [OM] S Zuiko 100~200 f/5 Question
> >
> >This is quite normal for this model -- that, and the zoom tends to slip when
> >you point it downwards. The rollers wear out, but they are no longer
> >available. We've experimented with adapting parts from another lens to
> >correct
> >this....
>
> Normal WEAR? Would this suggest that, even though the lens appears to be in
> mint condition, it actually has a lots of use, or are the internal parts of
> this lens less rugged than other Zuiko designs (given that it is a S
> Zuiko)? I do notice a slight change in the drag of the barrel at either end
> of the zoom range, but the focus is smooth throughout.
>
> >Curtis P. Hedman wrote:
> >
> > > I have a new (to me) S Zuiko 100~200 f/5 zoom, and I would like to poll
> > > the
> > > List experts on something I noticed about the lens: the helicoid focus
> > > mount stop is a fair amount beyond the infinity mark on the lens barrel.
> > > When using the lens, I find that the infinity (or at least long range)
> > > focus point is about where the infinity mark is on the barrel - i.e. the
> > > lens can focus 'beyond infinity' [or to quote Buzz Lightyear in "Toy
> > > Story", "To Infintiy and Beyond"! Does anyone know if this is typical of
> > > the 100~200? Or perhaps of the S Zuiko series? The lens I have is in
> > > beautiful shape cosmetically, and takes very sharp pictures, so I don't
> > > see
> > > this 'over focussing' as an issue.... more of a curiosity point. Any wise
> > > words will be appreciated! Curt
> > >
> >
> >------------------------------
> >
> >Date: Tue, 28 Aug 2001 14:19:01 -0400
> >From: "John Hermanson"
> >Subject: Re: [OM] S Zuiko 100~200 f/5 Question
> >
> >The infinity focus of the 100-200 would register like a sine wave as you
> >zoomed back. Focus ring has to go a little beyond the infinity mark
> >because lens will not hold infinity.
> >
> >John Hermanson
>
> Contrary to the other response to my question, which says this behavior is
> due to internal wear, you suggest that this is the way the lens is designed
> - that it is slightly varifocal versus a true zoom, at least at infinity.
> Given the 'one touch' design this would not be much of a problem
> operationally, but it still comes as a bit of a surprise! Do any other
> Zuiko zooms exhibit a similar behavior?
>
> I emotionally prefer John's answer, as it means my lens might not have
> significant wear! Unfortunately Paul Schings' response notes his 100~200
> does not seem to exhibit the 'beyond infinity' condition.... anyone else
> care to put in their two cents on this one? I plan to see if I can observe
> the sinusoidal infinity position with my copy of the lens in the next day
> or so.....
>
> Thanx for all inputs, as always.
>
> Curt
>
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