[KOML] Focusing Q with Different Lenses

[Tom Cogbill <zloi@seanet.com>]

                   *** WARNING ***

This mail has originated outside your organization,
either from an external partner or the Global Internet.
     Keep this in mind if you answer this message.


I have been scratching my head lately over the following: I recently
acquired
the 180 and 58 mm lenses for my K-O 200.  Now when I have the standard
90 mm
lens on and focus through the rangefinder (RF), the two images inside
align pretty much in accordance with the distance, as I have measured
it, up to  about  15 ft (and probably thereafter, as well—I just haven’t
measured it any farther).  When I switch to the 180 lens, and look
through the RF, everything stays exactly the same—the two images
coincide at the same distances as before, using the 90.  I thought
nothing of this, until I noted that the 180 and 58 lenses have their own
focusing scales on the outside of the knob, but when the RF images
align, telling me I am in focus, the actual distance in no way
corresponds to the distance on the 180 scale.  For example, at 12 actual
ft., which is supposed to be the closest distance at which the lens is
usable, the 180 scale tells me the distance is about 40 ft.
Furthermore, this is the earliest point at which the inner rectangle is
fully formed inside the RF (corresponding to the field of view for the
180 lens).  This seemed crazy, so I thought the problem was just that
the scale was misaligned.  Moron that I am, I pried off the outer scale
(leaving a scratch or two, of course) and tried to reglue it in the
“correct” position, only to realize that, if I re-stick it such that the
12 ft. mark corresponds to where it had been showing 40 ft., the
focusing knob can only rotate slightly more before maxing out (--15 ft.
in the new position), leaving the rest of the scale useless.  Meanwhile,
the scale for the 90mm shows the right distance—so is the RF calibrated
only for that scale?  If so, then why bother having scales for the other
lenses?

I’ve been told that the silver post(s) on the top right of the lens
where it attaches to the camera tells the camera what lens is being
attached.  In other words, the camera “knows” each different lens.  Is
there something wrong with my camera, then?  Should the RF change,
depending on which lens is attached?  If not, I can’t see how the
different scales could ever possibly be useful and correct.  The inner
rectangular box really needn’t even show up the RF when the 90 mm is
attached.  But when the 180 is on, the inner rectangle should show up
right away, with the knob maximally “in” and the 180 scale reading 12
ft.  Otherwise, the rest of the scale will be useless.  So, I’m
buffaloed--what is gives here?

Thanks—and sorry about the long-winded description,
Tom