Sekonic L-398 - Lumigrid

2.
Lumidisc
Employ
for illumination
contrast
adjustment
and
luminance
measurement.
o
contrast
measurement
a.
Mount Lumidisc @
to
light
sensor
@
.
lnstall
in the
same
manner as
Lumisphere.
b.
Hold
meter at
subject
Position
and
point
Lumidisc
@
di-
rectly
toward
center
of
main
light.
c.
Press stopper
button
@
and
read
meter
scale
f
ootcandle
indication
@
.
d.
In the same
manner,
read
the
fill
in
light
footcandle
indi-
cation
@
In this case,
use
care
that
light
f rom main
source
does
not
enter sensor.
e.
Ratio
between
main
and
fill
in
light
footcandles
becomes
the contrast
ratio.
Example:
With main
light at 640
footcandles,
fill in
light
reads
320
footcandles.
I
llumination
contrast
ratio becomes:
#=i
or2:1
Luminance
(lux)
measurement
Mount
Lumidisc
@
to
light
sensor
@
in the
same
manner
as
Lumisphere.
b.
c.
Place
Lumidisc
@
parallel
with the
measured surface.
Press stopper button
@
and
read meter
scale
footcandle
indication
@
d.
Multiply this
value by
10.76 to
obtain
Example: 80
x
10.76
=
860.8
lux
lf meter
def
lects beyond
scale,
insert
High
footcandle
indication by 32.
Example: 80
x
32
=
2560
footcandles
2560
x
10.76
=
27545.6
lux
Reflected
Light
Measurement
1. Lumigrid
a.
Mount
Lumigrid
@
to
light
sensor
@
in
the
same
manner
as
Lumisphere.
Set
sensitivity
value
of
em-
ployed
film.
Setting
is
per-
formed
in the same
manner
as
for
incident
light
measurement.
Point Lumigrid
@
directly
toward
part
of subject
to be
measured.
As
close as
possible
to the
subject,
measure
ref
lected
light
from main
point
of
subject.
Use adequate
care at
this
time
that
meter
shadow
etc. does
not interf ere.
lux.
slide
6,thenmultiply
b.
o
a.
11
light
d.
www.orphancameras.com