Operation Manual

DETERMINING
GUIDE
NUMBERS
FOR FLASH
The
Flash Meter
lV can be
used to determine
the
guide
number
for
the
actual
film speed in
use.
1.
With
the
desired
film
speed
set and
the
measuring-
mode selector
set
for
"CORD"
or
"NON.C"
operation,
move the
display-mode
selector
to
"ExlN",
then
attach
the optional
flat diffuser.
2.
Position
the
meter
at
a specific
distance
(e.g',
3
meters
or
10
feet)
from
the
flash
unit
and
point
the
diffuser directly
at
the
flash.
3.
Press
the
measuring
button
all
the
way
in to
activate
the
meter's
circuit.
Then, trigger
the
flash
manually.
Read
the displayed
information
in the
formula
below
to
determine
the
guide
number:
r+
GN=
1.14xLx2
z
Where
L
=
Flash-to-meter distance
Example
With
a
display reading
of
"ExlN
10.0" at
ISO
100
and a
flash-to-meter distance of 1
meter,
work
the
following
equation
as
follows:
10
GN=1.14x1x2'
=1.14x1x2s
=
1.14
x
1
x32
=
approx.
36.5
',ffi
MEASURING
ILLUMINANCE
To
measure illuminance of a continuous
light source:
1.
Set
film speed to
ISO
100,
measuring
mode
to
"AMBl",
and
display
indication to
"ExlN".
Attach
the optional
flat diffuser.
2.
Position
the
diffuser
parallel
to and
as
close as
possible
to the surface
where
light
is to
be
meas-
ured.
Push
the
meter's measuring
button.
3.
Read the
"ExlN"
value
and
use it in the
following
formula:
lux
=
2.5 x2"'*
Lux
100,000
10,000
1,000
100
10
1
o246810121416
lExlN.l
Example
With
a
display reading
of
"ExlN
10.0"
work
the
equation as
follows:
lux
=
2.5
x2'*'*
=
2.5
x 21o'o
=
2.5
x
1O24
=
approx. 2600
NOTE
o
For
precise
measurement
of illuminance,
use
of
the
Minolta llluminance Meter
is
recommended.
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