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Hello All,
While clearing some junk out of the basement recently I came across=20
a gear which I made from scraps, decades before e-mail,(~1975 ?) for=20
stereoscopic viewing of air photos. It consisted of two mirrors held 7"=20
apart in slots cut at a 45 degree angle in thin boards, one mirror=20
facing up & one down. A low table lamp is required so that the portion=20
of air photo below the down facing mirror is illuminated.
In use, the area of interest was placed below the down facing mirror=
=20
and a full size image would then appear in the up facing mirror. For=20
purposes of visualization let the down facing mirror be on the left. The=20
corresponding area of the second air photo would then be placed one eye=20
spacing to the right of the up facing mirror. If the photos are arranged=20
with edges parallel then the whole assembly can be moved around without=20
adjustment.
For viewing I used two cheap reading lenses about 2" in diameter.=20
Tilting one or both a bit, one over the up mirror, one over the right=20
air photo enabled fine distance adjustment for stereoscopic viewing.
With this long preamble out of the way, and with likely most=20
naturensers reading something else, I can now get to the point.
A few years after I joined Naturens the subject of expensive=20
stereoscopic viewers came up and I mentioned having designed and made=20
this device from disposables.
Observation: it worked fine even for those who had never previously=20
seen stereoscopic images of air photos.
Dogma: someone chimed in with the objection "that can't possibly=20
work."
I have noticed this conflict between observation and dogma many=20
times on Naturens, especially in recent posts with respect to Old Growth=20
and wildlife e.g Moose. Over the years I have walked over a lot of=20
woodland, sometimes for hunting but mostly for the fun of seeing what=20
was over the next rise etc. And without exception, woodland of large=20
widely spaced trees is country either avoided by animals or crossed in a=20
bee line. Disturbed cover, on the other hand, clearcut or selectively=20
cut by human, by wind throw or by Spruce Budworm quickly become more=20
alive. Former Beaver desert became Beaver heaven when the Budworm killed=20
Fir and Spruce and generated space for hardwood thickets. Twenty or so=20
suckers which sprouted from the stump of a large Ash which I cut January=20
2017 were gnawed to stubs by July.
Just a rhetorical question but I wonder how someone comes to the=20
conclusion that ancient woodland is the best possible type of cover ?
YT, DW, Kentville
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<body>Hello All,<div>=C2=A0 =C2=A0 While clearing some junk out of the base=
ment recently I came across a gear which I made from scraps, decades before =
e-mail,(~1975 ?) for stereoscopic viewing of air photos. =C2=A0It consiste=
d of two mirrors held 7" apart in slots cut at a 45 degree angle in thin bo=
ards, one mirror facing up & one down. A low table lamp is required so=
that the portion of air photo below the down facing mirror is illuminated.=
=C2=A0</div><div>=C2=A0=C2=A0=C2=A0=C2=A0In use, the area of interest was p=
laced below the down facing mirror and a full size image would then appear=
in the up facing mirror. For purposes of visualization let the down facing=
mirror be on the left. The corresponding area of the second air photo would =
then be placed one eye spacing to the right of the up facing mirror. If th=
e photos are arranged with edges parallel then the whole assembly can be mo=
ved around without adjustment.=C2=A0</div><div>=C2=A0 =C2=A0 =C2=A0For view=
ing I used two cheap reading lenses about 2" in diameter. Tilting one or bo=
th a bit, one over the up mirror, one over the right air photo enabled fine =
distance adjustment for stereoscopic viewing.</div><div>=C2=A0 =C2=A0=C2=
=A0</div><div>=C2=A0 =C2=A0 With this long preamble out of the way, and wit=
h likely most naturensers reading something else, I can now get to the poin=
t.=C2=A0</div><div>=C2=A0=C2=A0=C2=A0=C2=A0A few years after I joined Natur=
ens the subject of expensive stereoscopic viewers came up and I mentioned h=
aving designed and made this device from disposables.=C2=A0</div><div>=C2=
=A0=C2=A0=C2=A0=C2=A0Observation: it worked fine even for those who had nev=
er previously seen stereoscopic images of air photos.</div><div>=C2=A0 =C2=
=A0 Dogma: someone chimed in with the objection "that can't possibly work."=
=C2=A0</div><div><br /></div><div>=C2=A0 =C2=A0 I have noticed this conflic=
t between observation and dogma many times on Naturens, especially in recen=
t posts with respect to Old Growth and wildlife e.g Moose. Over the years I =
have walked over a lot of woodland, sometimes for hunting but mostly for t=
he fun of seeing what was over the next rise etc. And without exception, wo=
odland of large widely spaced trees is country either avoided by animals or =
crossed in a bee line. Disturbed cover, on the other hand, clearcut or sel=
ectively cut by human, by wind throw or by Spruce Budworm quickly become mo=
re alive. Former Beaver desert became Beaver heaven when the Budworm killed =
Fir and Spruce and generated space for hardwood thickets. Twenty or so suc=
kers which sprouted from the stump of a large Ash which I cut January 2017=
were gnawed to stubs by July.=C2=A0</div><div>=C2=A0 =C2=A0 Just a rhetoric=
al question but I wonder how someone comes to the conclusion that ancient w=
oodland is the best possible type of cover ?</div><div>YT, DW, Kentville=C2=
=A0</div><div>=C2=A0 =C2=A0=C2=A0</div></body></html>
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