Nikon Eclipse Ti Series User Manual

Principles
of
DIC
Microscopy
since
the
human
eye,
cameras,
and film
caprure
images
by recording
differences
in
light
intensity
and
cotor,
they
do
not
register
colorless,
transparent
cells
or
baCreria.
Although
dyes
can
be used
to
make
these
transparent
subjects
visible'
the
dye
itself
kills
them.
The
differentiàt
inteterence
"onira.i
iòio*i,ni"ro""op"
was
deveroped
in
order
to
permit
the
observation
of
transparent
subiects
whire
they
are
.tii
"ìiul.
The
basic
structure
of the
Drc
microscope
is
the
same
as that
of
an ordinary
microscope,
except
that
it
includes polarizing
plates
and
wollasîon prisms'.
inese
ffiat
erements
change
a transparent
subject
into
different
levers
of right
inlensity.
In
other
words,
wnen
yoLr
ioot
inrough
a Drc
microscope,
you
see
even
]!Tqlt:tt
tYb.,."cts
as
jmages
consisting
of
different
rivets
of tighr
inìtensity.
1-ruomaÀiibíi"iJ-"r"
"rro
used
as a
variation
of Wollaston prisms.)
The
principles
of
a DIC
microscope
are
discussed
below
Light
refracts
as
it
passes
through
a subject,
even if
it is
a colorless,
transparent
subiect.
lf
the refractive
index
of
a subject
is
ditferent
Írom
that
of.its
surroundings,
light
thar
passes
through
the
subject
will
reach
a
ceiain
destination
point
faster (or
sloweo
than
light
thaipaéés
through
the
sunounding
material.
In
short,
when
lighî
passes
through
a
subject,
it
undergoei
a
pnaée
cnanje
lwitn
me
pnase
eitÀJ,
jJffi
an"aa
o,
being
delayed).
A subjecl
whose
only
effect
on light
is
a
phase
change
is
called
a "phase
subject."
See
Figure
g-l
on
the rightl
A
wavefront
of light
that is
originalty
in
the
same
phise.
indicated
by
a single
straight
line,
changes
when
it
passes
through
a
phase
subiect,
so
that
onty
th;
light
lhat
passed
through
the
subject
traveled
faster
than
thelight
that
did not.
This
phase
change
happens
when
light
passés
through
a
mtcrosoope
specimen,
with
the light
passing
through
the
specimen
traveling
either
faster
or slower
than
the-
surrounding
light.
Now look
at Figure
3-2. This
diagram
illustrates
the
principles.of
a DIC
microscope.
In
the
diagram,
the light
source is
located
on
the left,
so
the light
travels
from
Éft to
right.
A
polarizing
plate
and
a Wollasion
prism
are each
placed
on the
condenser
side
and
the
obiective
side.
When
the
light from
the light
source
passes
through
pol3îiilS
plate
1
(th€
potarizeo,
il wiil
be
potaize-cr
(changed
to light
that
vibrates
in
one
direction
onty).
When
thià
polaized
light
passes
through
Wo
aston
prism
f
,
it is
sptit
into
two rays
that
have
mutually perpendicular
planes
oi
polarization
(direction
of vibration);
the
two
rays
travel
at
a
slighl
distance
from
each
other.
Polarlzing plate
1
Figure
3-2
Principles
of a
DIC
microscope
since
wollaston prism
1 is
on
the front
focal
plane
of
the condenser,
the two
rays
pass
through
the
specimen
in
pafallel,
at
a slight
distance
from
each
other.
The
distance
between
the rays
is
called
the
,shear."
since
the
shear
is set
berow
the resorving power
of
the
ob,ectivé,
tne specimen
does
not
appear
as a
doubre
rmage.
lftel,tlte lwo
rays
pass
through
the
specimen,
they
are
collected
by the
obiecîive
onto
the
back
focat
ptane
of
the
obiective.
wollaston
prism
2 is
placed
here
toiecombine
tnà
two
rays
'uacr
ino
on".-
Àorràu"r,
the
rays
do not
intefere
w*h
each
other
since
they
have
p€rpendicutariLnes
ot
poraization.
l9111zjno
plate
2
(the
analyzer)
is
placed
so
that
th€
direction
of
potarization
is
perpendicutar
to that
of
polarizing
plate
I
,
taking
out
opposite
phase
planes
in
tne tight.
where
the
speòiméÀ
oio
noì"i"ng"
tn"
phas.e
of
the.light,.the
two light
rays
intelere
with
"""h
otn"i,
,""r.ening
them
and
m"iinf
tno.à
"r"".
m rn"
vi€xffi€ld
dark'
where
phase
obiects-in
the
specimen
cnangóo
the
phase
of the righî,
the
two right
rays
oo
not
interfere
with
each
other,
so
those
areas
in
the viewfield'appeai
urignt.
rnis
oiieiencein
urightness
is
how
the
DIC
microscope
makes phase
objects
visible.
WavofÌont
aft€r
passlng
through
spocimen
\
I
(
Wavgfroflt
SD€cimen
>l
nl
Yal
lt
l subjecl
Pfrase
Figure
3-l
Phase
changas
10

Nikon Eclipse Ti Series Specifications

General

Brand	Nikon
Model	Eclipse Ti Series
Category	Camera Accessories
Language	English