Archived posting to the Leica Users Group, 2000/08/29
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Hi Luggers,
Just has a look at the new Leica web site. Gotta go with the flow on
this one, not only is it slow to load, with sparse information, its
inaccurate!
On:
http://www.leica-camera.com/kultur/mythos/innovationen/messsucher/index_e.html
The following is claimed:
The angle of the mirror surface of the beam-splitting prism is polished
with an accuracy of one minute of arc. Applied to the distance from London
to Paris, an imaginary straight line emanating from London would strike
a person standing there with outstretched arms.
Now, the distance between London and Paris is about 350Km, in air miles. An
angle subtending an arc minute at 350Km covers about 100 meters, not the 2
implied by the statement. They probably meant arc seconds, which is 1/60 of
100 meters, or 1.6 meters, which is in the ballpark of "outstretched arms".
Picky Picky Picky!
We do expect more of Leica.
To continue to pick, let's say that mirror is 1 cm across. To adjust it's
angle with respect to the camera's Axis to within an arc second wild imply an
accuracy of 484 Angstroms. An Angstrom is about the size of an atom. It's
actually doable with today's better industrial grade tools.
Leica probably does achieve this standard of accuracy, even if they don't know
minutes from seconds.
Tom