Gossen MetraWatt Luna-Pro sbc User manual

-
GOSSEN ®
Luna-Pro
sbc
Instruction Manua l
7909-1057YO

This Luna-Pro sbc Instruction Manual is more
than just
an instruction book - it is actually a short
course
in the creative use of an exposure meter.
Section I offers "Basic Operating Instructions".
To
use your Luna-Pro sbc properly you need only read
and follow the simple instructions
in this section.
Section
II, however, moves a step forward -to
"Getting the Most Out Of Your Luna-Pro sbc." Here
you can really find out how to put the unique
versatility of your Luna-Pro sbc to work for you.
Section
III gives you "Helpful Hints" for special
shootings -action, snow and sand, sunsets, night,
and more -the type of information you need for
that extra creativity.
And Section IV provides you with full details
on the
"Accessories" for your Luna-Pro sbc -to turn it into
a true exposure system.
We sincerely hope that this manual will be of help
to you and will answer most of your exposure
measurement questions.
If it does not, feel free to
contact your specialist dealer.
In addition, our Con-
sumer Service Department is available for help
with special requests.
2
Cong ratu lations!
You now own one of the most advanced ex-
posure meter, the heart of the Luna-Pro sbc
System.
The new Luna-Pro sbc System is the most flexible,
versatile and adaptable photographic light measur-
i ng system ever devised, while at the same time
being very simple to use.
In order to get maximum
benefit from the quality design and operating fea-
tures of this precision instrument, please take a few
minutes to
read this instruction manual.
Your new Luna-Pro sbc utilizes the latest advances
in silicon cell sensors and also high performance
electronic circuitry including integrated circuits to
provide fast, accurate, repeatable readings under
the most difficult professional conditions.
The Luna-Pro sbc represents a most significant
development by Gossen GmbH, Erlangen, West
Germany, Europe's largest manufacturer of preci-
sion electrical instruments since 1919, and one of
the outstanding pioneers in exposure meter design
since
1932 .

Table of Contents
Section I. Basic Operating Instructions . 5
I. a. Zeroing the Meter . . . . . . . . 5
I. b. Inserting&Changing the Battery 5
I.c. Setting the Film Speed . 6
I. d. Exposure Factor Scale . 6
I. e. Making a Measurement . 7
I. f. Reading the Scales . . . 7
Section II.
Getting the Most Out Of Your Luna-Pro sbc . 10
II. a. Continuous or Stored Readings . . 10
II. b. The Null Method of Measurement . 11
II. c. Exposure Correction Dial . 12
Il.d. Footcandle Readings
with the Luna-Pro sbc . . .
13
II. e. Carrying Case . . . . . . . 14
11.1. Methods of Measurement . . 14
Il.g. Incident Measurement . . 17
II. h. Reflected Measurement . . 18
II. i. Scene Brightness Range . 19
lI.j. Color Crossover. .21
Il.k. Zone Systems . . . . . . . 21
11.1. Film Reciprocity Failure .... .
Il.m. Intermediate f/stops .. . ... .
Il.n. Intermediate Footcandle Values
and Exposure Time . . . . . . .
Section III. Helpful Hints . . . . . . .
Ill.a. Choosing Between Action Stopping
Ability and Depth-of-Field .
IIl.b. Snow&Sand .
IIl.c. Sunsets .. .
Ill.d. Night Lighting . . .
II I.e. Backlighting .. . .
111.1 . Copying ..... .
Ill.g. Excessive Skylight
Ill.h. Bellows (Extension) Factor
Section IV. Accessories . . . .
Section V. Using Luna-Pro Attachments
Section VI. Appendix . . . .
Service ......... . . .
Specifications . . . . . . . . .
Additional Reference Material
24
24
25
26
26
27
27
28
28
29
29
29
32
37
38
39
40
. 41
3

Operating Parts & Scales
1.
Spherical Diffuser
2.
Green Zero Check Point
3.
Meter Needle
4. Power Switch
5.
Cine Scale
6.
Electronic Flash
Reference Mark
7.
Battery Test Button
12
8.
ASA IndexTriangle
21
9.
Film Speed Scale
10. Exposure Correction Dial
13
11. Computer Dial
14
12. BatteryTest Zone
15
22
13. Exposure Correction Signal
14. ExposureTime Scale
15. Aperture Scale
16
16. Film Speed Setting Disk 17
17.
Exposure Value Scale
18
18. Exposure Factor Scale
19
Index Mark 23
19. Zone System Scale
20. Measuring Cell Window
(under diffuser)
21 . Zero Adjusting Screw
22. Table of Footcandle and '.
Lux Values
23. Battery Compartment Lid

Basic Operating Instructions
The following instructions are a quick operating
guide to the Luna-Pro sbc. For best results, also
read the additional sections describing in more
detail the different functions of the Luna-Pro sbc.
La. Zeroing the Meter
With the battery removed, check to see that the
meter needle
(3) rests on the green zero check point
(2) . If not, turn the zero adjusting screw (21) until
the needle rests on the zero mark.
ca . Lux
mit Diffuso~
bei 18 DIN
'e'
Ie
appr o
I. b. Inserting & Changing the Battery
Your Luna-Pro sbc is supplied with a 9-volt battery
which fits into the battery compartment
at the bot-
tom of the meter. Slide the battery compartment lid
(23) off and attach the battery to the battery clip
inside. Note that the battery can only be connected
one
way. Insert the battery into the battery com-
partment and slide the lid back
on . Check the
battery
by pushing and releasing the power switch
(4) and then pushing in and holding the battery test
switch (7). The meter needle should be well within
the battery test zone
(12) .
5

I.c. Setting the Film Speed
Determine the ASA speed from the data supplied by
the film manufacturer. Rotate the clear film speed
setting disc
(16) by the raised bars until the ASA
speed number
is opposite the white ASA index
triangle (8). A detailed ASA film speed table is on
page 36.
I. d. Exposure Factor Scale
Check to make sure that the exposure factor scale
(10) index mark (18) is at 1. A more detailled expla-
nation of this useful scale is on page 9.
6

I. e. Making a Measurement
Select the method of measurement desired, either
reflected or incident. (For details
on inciden1 vs .
reflected measurements, see section II. f. For
reflected readings slide the spherical diffuser
(1) to
either side of the meter. For incident readings,
slide the sperical diffuser
in front of the measuring
cell window (20) unit it "snaps" into the detent.
Aim the meter at the subject for a reflected light
reading or
at the camera for a incident reading.
Depress
and release the power switch (4 ). Rotate
the computer dial
(11) until the meter needle is over
the "0" null line. Read the desired combination of
f/stops and shutter speeds on the computer scales.
NOTE: When you release the power switch, the
value measured at that moment will be automati-
cally read,
and electronically stored by the Luna-
Pro sbc. To conserve battery life, the meter
switches itself off automatically after 30 seconds,
and your measurement set on the computer dial
remains for convenient
and repeated reference.
For continuous measurements, see page 10.
I. f. Reading the Scales
The Luna-Pro sbc has six scales used to give you
information on ASA index, aperture, shutter speed,
cine speed, exposure value
(EV) , and exposure
factor (EF).
In addition, accessory clip-on scales
are available for direct reading of other light
measuring values such
as footcandles.
7

The time, or shutter speed scale is calibrated from
1/4000 of a second to 8 hours and indicates values
as follows:
Hours are indicated 8h, 4h, etc.
Minutes are indicated 30m,
15m , etc.
Seconds are indicated 30 , 15 , etc.
Fractional seconds are indicated '2, '4, etc.
Note that each section
is alternately colored from
the adjacent sections for ease of reading. The red A/
indicates the proper reading point when using the
electronic flash attachment. See page 34.
The ASA scale is calibrated in standard ASA values
from 0.8 to 100 ,000 (100K). Intermediate values
are shown by short lines. A complete table listing
these intermediate values is on page 38 .
CAUTION: Because of the extreme measuring
range of the Luna-Pro sbc, it
is possible -under
exceptional conditions of very high or low light
levels combined with a very high or low ASA index
-that the computer displays both ends
of the expo-
sure time scale (8h and 1/4000 sec.) When this
occurs, the CORRECT reading
will be the
UPPER part of the scales!
8
EXAMPLES:
ASA 25,000 at HIGHEST LIGHT LEVEL:
Scales.show (above) 1/4000 sec. at
11128
but also (below) 8 hours at f/5.6 etc.
Obviously, HIGH ASA and HIGH light level add up
to SHORT exposure -1/4000 sec. at f/128.
ASA 0.8 at LOWEST LIGHT LEVEL:
Scales show (above) 8 hours
at f/2.8 etc.
but also (below) 1/4000 sec. at f/64
etc.
Obviously LOW ASA and LOW light level add up
to LONG exposure - 8 hours at f/2.8.
The apertu~e or flstop scale is calibrated from fl 128
to f/ O.7. Numerical values are shown on the scale at
full flstop increments. Intermediate values are indi-
cated
by short lines at 1/3 stop increments. A table
of intermediate values and the mathematical for-
mula for calculating f/stops are given in section III.
The zone system scale indicates values from I to
IX.These are the values commonly used in various
zone systems and represent a continuous grey
scale of print values ranging from black to white.
Further explanation
on use of zone system scales
are given in Section II. k. .

The cine scale allows direct reading of apertures
for various cine speeds
(f rames per second).
These speeds correspond
to actual exposure times
on the exposure time scale only for cameras hav-
ing standard shutter angles. For XL cameras or
those with adjustable shutter angles, consult the
camera's instruction book for the equivalent shutter
speeds
and read your exposure opposite that
speed
on the time scale. Also note that some reflex
viewing movie cameras use beam splitters to pro-
vide a light path
to the viewing screen. These beam
splitters reduce the light intensity to the film plane,
so that a correction factor must be applied to the
indicated f/stop. Once determined, the correction
can be programmed into the exposure correction
dial.
An EV (exposure value) scale (17) is provided for
cameras with shutters calibrated
in EV. The Luna-
Pro sbc EV scale is calibrated from -8 to +24.
Numerical values are shown for full EV values with
intermediate values indicated
by short lines at 1/3
EV intervals. Exposure values are used elsewhere
on several scales which will be explained later. It is
important to remember that a change of 1 EV is
equivalent to a change of 1 f/stop.
An EF (exposure factor) scale is included for mak-
ing exposure corrections when using filters, bel-
_ lows, extension tubes, etc.
It is calibrated for expo-
sure factors
up to 64. Detailed information on this
scale is in section II. c.
9

10
Getting the Most
Out of Your Luna-Pro sbc
The preceding condensed instructions gave you
information
on the basic operating procedures for
your Luna-Pro sbc. However, this meter
is extre-
mely versatile, and the following information will
acquaint you with the many creative possibilities
available to you when using your Luna-Pro sbc.
Il.a. Continuous or Stored Readings
The Luna-Pro sbc is capable of either continuously
reading or storing light values. For simplicity of ope-
ration, the
read and hold method is used. For eva-
luation of different lighting levels such as when
using zone systems, the continuous method
is
used. Both methods are activated by the same
power switch.
To operate the meter in the read and hold mode,
the power switch
ON /OFF button index mark (a)
must be aligned with the square switch position
indicator
(b). Simply depress and release the
power switch. The meter will automatically read
and electronically hold the value of the light level
present at the moment when the button was relea-
sad. Because advanced electronic circuitry
and a
silicon blue cell are used in the Luna-Pro sbc, the
measurement
is instantaneous with no memory or
lag. This reading will be stored and available for a
period of
30 seconds after the button is released.
After the one minute period,the meter automatically
turns itself off, prolonging battery life. Additional
readings can be taken at any time by repeating the
above sequence.
To operate the meter in the continuous mode, sim-
ply depress and hold the ON /OFF button in. The
meter will now respond
to all changes in light
values. For long term measurements, the
ON /OFF