Gossen LUNASIX3 User manual

CONTENTS
                        Page                               Page
Basic operating instructions          The personal touch .           19
                                     Motion and depth of field .     14Setting the film speed
Reflected/incident
measurement                   3      Technical appendix          .  18
Light measurement  (basic)      4      Reading the scales   .      .19
Light measurement  (specific)    5      Exposure modification    .    .21
Testing the batteries            7       Reciprocity effect        .23
Testing zero position           7

                                  The LUNASIX 3 SYSTEM
Thinking and measuring
                                Expanded capabilities .       26
Reflected light measurement
Measuring area of the
LUNASIX 3  .                       I
"Perfect" exposure   .            11

Digitally signed by Mike Butkus
                                        DN: cn=Mike Butkus, o=Butkus camera
                                           manuals, ou=butkus.org, email=mike@butkus.Mike Butkus org, c=US
                                              Date: 2022.08.10 17:10:15 -04'00'

                     @ Diagnam showing conrect position
                                                                 of the 2 batteries

                     @ Battery Chamben

                     @ Ridged Slide fon
                                                              batteny testing

                             ezx Tableequivalentsof footcandle (Lux)

                      @ Tero Adjustment Srew





               Technical alterations resenved

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 Introduction to the LUNASIX 3

 The LUNASIX 3 is the finest in the line of "SlX" Exposure and Colour Temperature Meters                                                                                       - the slXTUS, stxroMAT, stxoN, Btstx, stxflNo, polystx and StXTtcoLoR _ made by the worldfamous manufacturers

           GOSSEN


LUNASIX 3 is the name given to this finest of all Exposure Meters because the LUNASIX 3
can measure reliably any light from the palest mooniignt to the brightest sunlight.
And - even more important - the LUNASIX 3 is the first SysTEM EXposuRE METER.
It enables you, by means of instant-lock-on attachments, to refine your measuring tech-
niques not only in your camera work on location and in the studio, 6ut in enlarging or in
photomicrography, photography through terrestrial telescopes and for selective anddensity measurements.



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                                                                                     I

Basic Operating Instructions





Setting the film speed
Look up the DIN or ASA Exposure Index of
the film in use (you will find it on the film
box or film instruction sheet) and turn the
plexiglass film-speed setting disc (14) by the
raised bars, until the DIN or ASA Index
number is lined up against the triangular
white marker in the respective window.
You will find a detailed DIN-ASA film-speed
table in the technical appendix on page 20.

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                                                                               LV-            A;@ #                txr;U/\E

Reflected Light Measurement: Move the   Incident Light Measurement: Move rhe
converter slide (9) all the way to the right;    converter slide (9) so that the spherical
this uncovers the round window. The LUNA_    diffuser is centered over the round window.
SIX 3 is ready when the converter slide has   The LUNASIX 3 is ready when the converter
clicked into position. point the LUNASTX 3    slide has clicked into position. The LUNA_
toward the subject, as indicated by the   SIX 3 is pointed from the subject towards
arrow in the illustration.                     the camera, as indicated by the arrow in
                                          the illustration.

Llghl Measurement - (baslc steps)
 Press the range selector (12) backward and release  it when the indicator needle (2) stops
 moving. This locks the reading in for convenient reference.
  lf the indicator needle is deflected only slightly (below 12 on the scale), take a new reading
 by pressing the range selector forward. You have now switched the LUNASIX 3 to the low
 light range. Wait again until the needle stops, and lock the reading in by releasing the
 selector.
 lf the light is so poor that you cannot observe the movement of the needle, simply hold
down the selector for several seconds. After releasing it, you have locked in the correct
 reading and can take the LUNASIX 3 to better light, or use a flashlight to read the scale.
As you press the selector fonivard, the values 1 to 12 appear in the upper frame, and the
upper scale divisions apply, when you press the selector backward, the values 12 to 22
appear in the lower frame to which the adjacent lower scale divisions apply. When you
release the selector, only the scale values applicable to the measuring range which youjust selected, remain visible.
Thus, the LUNASIX 3 always shows the correct scale!
After taking the measurement, turn the computer ring (7) until the obtained reading is set
at the triangular yellow index (17) of the transfer scale (15). The green and red ring indexes
apply only for measurements with the Variable Angle "spot meter" attachment. See page 2g.
4

With inaccessible  subjects, take the incident
light measurement at a substitute spot
which receives the same illumination as the
subject. However, instead of pointing the
LUNASIX 3 towards the camera, you point  it
parallel to an imaginary line from the object
to the camera.
Incident light measurement at a substitute
spot of equal illumination is also convenient
for many regular outdoor scenes. Frequently'
the spot where you stand with the camera
receives the same illumination as the scene
which you intend to photograph, in which
case you merely do "about face" with your
LUNASIX 3 and measure the light exactly
opposite to the direction of the camera.
More about this on Page &11.

6

Thinking and Measuring



One thing the LUNASIX 3 can not do: lt cannot think for you! Even the most advanced
"electronic brain" is helpless without the scientist who phrases his problems so that they
can be processed by the computer. The LUNASIX 3, too, answers exposure questions all
the more precisely,  if you ask more carefully! You will find this quite easy once you become
familiar with your LUNASIX 3.
Above all, you must know how your LUNASIX 3 sees the world that you want to get on your
film. This wortd is made up of many parts, which differ considerably in size, colour and
brightness. ln the case of reflected light measuremenl, the LUNASIX 3 collects, within a
cerlain angle, the light which is reflected from these many individual parts of the scene;
 it adds up all the light and strikes an average for which it indicates a suitable exposure
time. And, normally, the exposure indicated in this manner is perfectly correct. (Reflected
Light Measurement, see also pages 3 and 5')
Anything unusual which you - as attentive (!) observer - will easily notice, may not be ,,seen,, by the LUNASIX 3 in quite the same manner. lf the scene includes a large very
bright ar"a - far from the "average" that the LUNASIX 3 would normally calculate with -  it

8

answer! For the amateur, especially the beginner, the over-all impression is usually
decisive. But soon the demands become more stringent, especially when results are com-
pared. "Perfect Exposure" normally means: The brightest portions of a colour transparency,
the darkest portions of a black-and-white  print, should still show some detail!
For colour slide or movie film - which as you know, requires more critical exposure - the
lighter portions of a scene usually determine the exposure. Therefore, keep an eye on such
lighter areas and preferably expose a little shorter rather than longer, to get more brilliant
colours.
For black-and-white or colour negative film, however, the shadow portions which are to
have some detail in the finished print must be given consideration. Therefore, watch the
darker areas and expose a little longer rather than too little.
Most important: Be critical of your results! Analyze your prints and color transparencies  for
possible mistakes or errors in judgment. Learn from your experience: Failures properly
 analyzed will soon lead to consistent successes!
Remember, that, wh.en there are extreme contrasts in a scene, the film may not be able to
cope with theml Don't blame your LUNASIX 3! You will have to compromise with the
limitations of the film by exposing a step more or less than indicated by the LUNASIX 3'
About "exposure steps" see page 21. However,  it is easy to give your LUNASIX 3 your
personal Touch by harmonizing it with the tolerances of your camera, your favorite film,
your developing methods (or those of your finisher). Here is how:

12

Use a reversal colourfilm;selectseveral  "normal"scenes;takecareful  reflectedandincident
light measurements and shoot! But - each time make a series of 5 exposures; in addition
to the one at the indicated exposure time, make one each at a full step and one-half step
more and less than indicated by your LUNASIX 3. Make complete notes of the readings and
of any special conditions. When you have your finished transparencies, select the ones
which, in your judgment, are "perfect" and compare them with your notes concerning
exposure measurements, etc.
 lf they're O.K. - and in most cases they will be - everything  is fine. Otherwise, determine byhow much you need to increase or decrease future exposure readings to get the best
results. With this adjustment you have then gained your "Personal Touch".

Sharpness for Motion and Depth of Field
After you have taken a light measurement, the computer scales of your LUNASIX 3 may line
up something like this:
                                                                       Sec.time   lltooo llsoo llzso  lltzs  lleo  1llo   'lts    1lell     2   2.8  4   5.6  8   11    16      22
Eight combinations  of which you may really use only one! Now, which combination might
be "the best"? The LUNASIX 3 has done its best giving you so many equivalent pairs so
that you may select a really suitable one. After all, a properly exposed picture must also
be in sharp focus - which means that you have to ignore some aperture (f-stop) settings
and some shutter speeds.

14

The LUNASTX 3 as an Aid in Good Lighting
With effective lighting you can achieve outstanding pictures, either by dramatically  in-
creasing or lowering contrasts. But contrasts should not be overdone, because the film
may not be able to cope with them.
Baiance your lighting with the LUNASIX 3: Take a measurement of the key light, and then
of the - weaker - general light. Now, simply compare the two indicator scale readings(f-stops and shutter speeds are not involved in this method): For black-and-white  film' the
diflerence between the two readings should not exceed 3 steps; for colour film 2 steps
at the most.
 lf you want to achieve soft lighting with little or no contrast - as in high-key subjects or
copy work, arrange your lights so that you get identical meter readings at different arear
of the subject and background (if any). This type of lighting is usually preferred in colour
photography.

Night Mood
 lf you want to retain the character of the night with "darkness" and a minimum of visible
detail, simply use a shorter exposure than indicated by your LUNASIX 3; otherwise your,,night"       scene might resemble a daytime scene. Frequently, however, the "reciprocity
effect" produces the same result as a shorter exposure. There are no hard and last rules
about this. To gain experience, you might start off by using, without modification, the
exposure times indicated by your LUNASIX  3.
Reciprocity Effect For more information, see page 23.

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COLOUR  For street scenes at night, in moonlight and for illuminated signs, use day-                light film. Scenes illuminated by incandescent light (ordinary light bulbs)
           demand tungsten film; in borderline cases the daylight type film will usually
            produce more agreeable colours.





Snow
                                                                       It is simpler to use the
Reflected Light Measurement                   lncident Light Measurement
 In a snow-covered landscape, the measuring   because it indicates correct exposure al-
circle of your LUNASIX 3 is almost entirely   most directly.  lf you want to get special
filled by great brightness. The indicated ex-    effects - for instance the subtle shadows  in
posure would be too short, particularly when    the snow - decrease the indicated exposure
there are people, animals, or trees in the   by 1/z lo 1 step. Naturally, in this case, dark
foreground. Exposure modification of 1/z lo   foreground will show somewhat less detail
1 step should be made.                   and, in colour, have strongly saturated
                                                   colours.
                                      17   ll

Technical Appendix

The LUNASIX 3 Principte
 Unlike exposure meters whose photoelectric cell consists of a selenium element, the
LUNASIX 3 has a photo-conductive cell and is powered by tiny mercury batteries. While
a selenium element converts light into electric energy, the photo-conductive cell merely
changes its conductivity in the presence of light. The electrical energy which powers the
precision mechanism of the LUNASIX 3 to deflect the indicator needle is here supplied
by batteries.

Diagram of the LUNASTX 3
                                                    Photo conductive  cell


                                        Resistance for                           Batteries
                                                    calibration



                                                                Indicating instrument
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Reading the Scales


'2'4'8 etc. are fractions of seconds:  tlz - th - r/a sec. etc.
Un-marked numerals 1,2,4 etc. are full seconds.
1m 2m 4m etc. are minutes
t h 2h 4h etc. are hours


                                                                            exPosure

                                          Jil::"'ll"1ns

Cine frames per second and                                I
Note: On certain motion picture cameras, the exposure time at normal speed (16 f.p.s.) is
not 1/:o second. Check the instructions  for vour camera!

                                                                                              19

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 When exposure modiflcation is in order (see page 12), you simply choose one (and only
 one!) of the following adjustments:

                                                     One Stop
                                                            lf actual LUNASIX 3     more         less                                                                                I                                    reading  is, for example:   exposure I  exposure
                                                                    requires a change to:
                                      lndicator Scale 16              15              17
                           EV Scale 10                    9                11
                                     Shutter Speed i/ro                 1/rs                          l leo
                                 Lens Aperture f/5.6             4                 I
                                Note: The ASA setting remains unchanged!

Calibration Data
The table on the back of the LUNASIX 3 shows the approximate calibration data. These are
the footcandle and Lux values (1 ft-c :  10.76 Lux) corresponding to the LUNASIX 3 scale
readings obtained by the incident light measurement method. The LUNASTX 3 should not be
considered a full-fledged footcandle meter because, strictly speaking, footcandles  of
illumination can be measured only be means of a flat interception screen. The LUNASIX 3 is

                                                                                                      21

equipped with a spherical diffusing screen and thus achieves superior collection of the
photographically  effective illumination: Photographic subjects are usually three-dimensional
and they are illuminated from many different directions (sun, sky, reflections from buildings,
trees, ground, etc.). However, the footcandle table can be of practical value for measuring
direct light beams (arc light, spots).

For reflected llght measurement, footcandle values cannot be given at all, since this method
measures not the illumination but the brightness of the surface (field luminance) which can
be expressed in footlamberts. The measured values for reflected light measurement ex-
pressed in footlamberts are approx. 7.5 times smaller than the footcandle values with
incident light measurement. Example:

                                                        Incident light      Reflected light                                        lndicator                                                               (illumination  in      (field luminance                                    scale reading                                                           footcand  le)       in footlamberts)

                                                                            1                       .0'l75               .002
                                            2                    .035                 .004
                                            3                      .o7                    .008
                                            4                   1.4                     .016

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As a result of this calibration, a medium grey tone will be reproduced by black-and-white
as well as colour film with a density or colour value, respectively that lies approximately  in
the middle of the straight line of gradation. Thus, sufficient latitude exists in correct ex-.
posure for those parts of a scene which are lighter or darker than the "medium grey".
Reciprocity Effect
Film manufacturers base the "speed ratings" of photographic emulsions on average con-
ditions of exposure times and illumination under which such emulsions are "normally"
intended to be used. However, photography under poor light conditions may call for
"abnormally" long exposure times.
Black-and-white films, generally, tolerate moderate deviations from normal conditions. On
the other hand, reversal colour films - because of their limited latitude - not only lose
"speed" but their colour balance is also affected.
The reason for this divergence lies in the fact that the effective sensitivity of every photo-
graphic emulsion is at a maximum at some specific level of illumination. With variations
in illumination and exposure time, the effective sensitivity also varies, a phenomenon which
is called the "reciprocity effect".
Film of various types and makes react differently to extended exposure times, and it is
impractical to incorporate the many possible variations in the LUNASIX 3 scales.
 It is advisable to write to the film manufacturer for information concerning the necessary
exposure correction and filtering for colour correction of the specific film which you are
using with extended exposure times.

                                                                                      23

The LUNASIX 3 System


Thanks to its unique design as a SYSTEM EXPOSURE METER, your LUNASIX 3 provides
you with an adaptability and universality previously unknown in exposure meters.
Used alone, the LUNASIX 3 continues the superb tradition of the Gossen LUNASIX as the
world's most sensitive, widest range (1 :2,000,000) exposure meter. lt converts instantly,
and without accessories, from reflected to incident light measurement - and you'll find its
one-hand operation (even with a glove on) a gieat boon when moments count on location,
or in the studio.
Now, whenever the rieed arises, you can greatly expand the capabilities of the LUNASIX 3
by using one of the following exclusive accessory attachments:
     LUNASIX 3 Measuring probe attachment (see page 27)
     LUNASIX 3 Variable Angle "spot meter" Attachment (see page 28)
     LUNASIX 3 Enlarging Attachment (see page 29)
     LUNASIX 3 Microscope/Telescope  Attachment (see page 30)
     LUNASIX 3 Copying Adapter (see page 31)
An instant-lock-on device holds each attachment firmly on the LUNASIX  3.

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Measuring probe attachment
for the LUNASIX 3
The measuring probe attachment is
being used for selective measure-
ments on the ground glass of the
camera for spot metering at places
normally not accessible, in micro-
photography and macrophotography,
for determining the contrasts  in
negatives, and for density measure-
ments.

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 Enlarging Attachment
for the LUNASTX 3
Converts the LUNASIX 3 to an effi-
clent enlarging exposure meter for
black-and-white or colour enlarge-
ments. lt permits you to measure
very small areas of the projected
image for maximum utilization of
paper contrast and colour range.
Built-in light conductor (instead of a
mirror) for greater accuracy and
eff iciency.