Publicité
4
6
DEPTH-OF -FIELD
When
the
lens
is
fo cused on
a
subj
ec
t
at so me
di
stance, no
t
o
nl
y the
subj
ec
t but
also a
certain
area aro
und th
e
subj
ec
t
wi
ll
be
sharpl
y delinea
ted in
a pho
tograph
,
and
this area is
know
n
as
a
Depth-of-
Field and
has
the
foll
ow
ing
fea tures.
a. Th
e
bigger
the
fnumb
er,
th
e
larger
the
Depth-ofField.
b.
Th
e
farer
the
distance
at which th
e
lens
is
focused,
the
bigger th
e
Depth-ofField
is.
c_
When
the
lens
is
fo
cused
on a
subjec t, the
Depth-ofField
is
bigger f
or
the
section in f ront of th
e
subject than
the
area behind th
e
subject.
d.
Th
e
shorter
the
focal length
,
th
e
bigger th
e
Depth-of
Field.
The Depth-of-F
ield
may
be
ascer tained
either
wi
th th
e
depth-of-fi eld
sca le or w
ith
the manua
l
aperture.
As fo
r
details,
reference
is
made
to the tab
le
of depth-of-fie
ld
.
Using Table of Depth -of-Field
: T
he
Depth-of-Field
Sca le (7)
is so
calibrated
that rea
dings
identical
to those of the lens
aperture are prov
id
ed
on both
sides
of
the Distance Sca le
Index Mar
k
(55). For
example, let
us assume that the
distance between the
film plane and
the
su
bjec
t
o
n
which
a
50m
m
f/
L.4
lens has
been focused is
15 feet. The
Depth
of
F
ieLd
will
be
12
to
19 feet for f/
4 and
8
feet
to
~
(infinit
y)
for f/l
6.
INFR ARE
D FI LM
CO
MPE
NSA
TI
ON MARK
:The
point
of
focus is so mewha
t different in in
frared photogra
ph
y as
co
mpared
to no
rmal
photography
. After
the lens has
been
foc
used
as in
normal ph
o tography, rea
d
the calibratio
n
o
n
the Distance
Scale
(8)
aligned wit
h the
Dista nce Scale
Ind
ex
Mark (55)
and
bring
thi
s reading
in
li
ne wit
h
the
Infrared
Film
Co mpensation
Mark
(56)
before
the shutter is
released
fo
r
a
shot.
Depth-o
f-Field
fo
r
f/ 16
.
'
5
7
10 15 30(10
1.5
2
3
5
10"
~-1J.!.I
,
l!..~'--
16118&.84
4R81116
(55) Dista nce
Sca le
Index Mar
k
(7)
p th-of-F ield Sca le
(7) Schafentiefenska la
(8)
Ent
fer
nungsska
la
(55) Index
flir
Entfernung
Distance Scale
(56)
Infr ared Film
Co mpensa tio
n
Mar
k
(56) Ausg leichsmar kierung
flir
Infra rota ufna
hmen
(7) Eche lle
de
pro fo
ndeur
de champ
(8)
Echelle des
distan
ce
(55)
Repere
de
distan
ce
(56) Marq
ue
de
co
mpe nsa tio
n in
fra-rouge
(7)
Skiipdj
upsska la
(8) Avstllndsska la
(5 5)
A
v
s
t~
n
dsindex
(56)
Avst~nds
in
dex
for
in
frarod
film
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