Several Oly lenses (particularly the larger, longer zooms) were designed to
focus "past" infinity, where the focusing ring would turn past the center
point of the infinity symbol before hitting the stop. This is, I presume, to
allow for expansion/contraction of the optics and barrel.
The 75-150mm wasn't one of them, however - at the infinity stop, it _should_
focus sharply on a subject several miles away.
jowilcox <jowilcox@xxxxxxxxxxxxxxxxxxx> said:
> John,
> I'm convinced my 85-250 does the same thing. It is worst when it is cold,
> which makes me think it is a deliberate design thing. In other words, the
> lens is designed so that when it is warm it will not focus *short* of
> infinity. I'm a lot less concerned about the ability to focus beyond
infinity
> than not to be able to focus *to* infinity. I'd say live with it.
>
> Joel Wilcox
>
> >===== Original Message From John Hudson <xyyc@xxxxxxxx> =====
> >Today I became aware that my 75 / 150 no longer focuses at infinity at
> >the infinity marker on the lens barrel. Focusing at infinity is about
> >midway between the 30m mark and the infinity mark. By infinity I mean an
> >object at least five miles away.
>
>
> < This message was delivered via the Olympus Mailing List >
> < For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
> < Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
>
>
--
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
|