Re: [KOML] Ground glass Back

[Clive Warren <Clive.Warren>]

At 6:31 am -0800 5/11/99, Tom Cogbill wrote:

>It is interesting to note how many variations of the K-O series were
>produced.  It seems just about everybody has something different about
>theirs.  My 90mm lens requires a series filter, and so I just assumed
>the 180 and 58 I recently got would also, but lo and behold, the 180
>takes a standard 67mm!  Is this, 'go figure,' or did somebody make a
>modification along the way?
>
>Clive--
>Thanks for the 'close-up' info--pretty much as I suspected.  BTW, this
>is the second or third time I've heard about this "ground glass
>back"--but I have to confess, don't have a clue what this refers to.
>
>--Tom

Tom,

All the 135s and 180s take a 67mm filter.

The 58mm or 60mm wideangle lens (both the same glass etc) takes either a
series 7 filter or a 55mm filter depending on the age of the lens.  The
series 7 equates to a 54mm filter so a 55mm filter would be very hard to
screw in and would then be there for a very long time :-)

You can buy a series 7 to 55mm converter.

The 90mm lens has an insert which can be removed to give you a 49mm filter
thread.  See the archives for various discussions on how to do this using a
rubber bung.

The ground glass back is essentially a dummy film back with a piece of
ground glass located exactly where the film would be on a normal loaded
back.  You can then focus the image on the ground glass screen instead of
using the rangefinder.  This is useful if you can ever find extension tubes
for the Hexanon lenses which allow you to focus closer subjects but make
the rangefinder useless.

Still looking for both the extension tubes and a ground glas back - oh yes
and a 135mm lens as the Omegaflex 135mm is getting dangerously close to
being modified for the Koni, probably with some sort of extension
incorporated :-)  Just seems a shame to cut about a lens in such good
condition.



All the best,

             Clive   http://www.cocam.co.uk
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