Gossen POLYSIX Electronic User manual

Diffusing sphere for
incident light meosuremeni


           Viewlinder with         meosuring fields   2                                10 Reference lights
            Rocker swilch   3

          Adjustment ring   4
     Shuller speeds for low
            intensity ronge   5                                 11 Aperture scole
    Shutter speeds for high   6
             intensity ronqe

            DIN speeds 7                                12 ASA voiues

   lndicotion ol meosuring                                              '13 Fiim speed serting disk
               ongle set                                                          for DIN ond ASA
                                                  14 Meosuring ongle setting
                                                                                 lever (10, 20, cnd 50o).  Eyelet for corrying strop
                             www.butkus.us

1B Meosuring lens                 i6  Locking screw for
                                                 Bottery chomber
Di{lusing sphere for incident                              Raltar\/      l\/na      l\A/^  nae
light meosurement                          IEC R6 1.5 Volts

Pl|LYSIX                                            incorporated in a transistorized ,"      ., il                                                   circuit which includes two indicator """lights.,electnonic     i rne Oiat is adjusted untit both tights- are   I
The POLYSIX-electronic is a product of the  equally bright, after which the exposure  I
 house of GOSSEN; manufacturers of the  , reading can be taken. Exposure measure-world-famous LUNASIX, SIXTAR, SIXTOMAT,  I ments reach a new standard of precision
SIXTINO and BISIX exposure meters; also of  with this modern electronic measuring instru-
the SIXTICOLOR colour temperature meter,  1 m€nt. The POLYSIX-electronic  is also an
MAJOSIX enlarging meter and SIXTRON- lextremely versatile meter. Three measuring     ,electronic flash meter.                                                      I angles of 30o, 20o and 10o can be selected'
The POLYSIX-e|ectronic will solve all your  at will and permit adjustment of the measu-
exposure measurement problems quickly and  ring field to suit the subject. For example,    I
efficiently. An entirely new measuring system  a very narrow measuring angle is often use-   |
is used in this meter. A transparent grey  ful when used in conjunction with long focus    I
wedge is coupled to the operating dial and  lenses. lt is also possible to use the narrow
moves in front of the window of the CdS cell.  angle setting to isolate a small, important  I
Transmission of light through the window is  object or to measure different parts of the  ttherefore varied as it falls on to the CdS  subject and produce a subject brightness
photoresistor and thus the electronic current  ,ratio. For incident light readings, the POLY-
flowing through the resistor varies dependingwww.butkus.usSIX-electronic is provided with a diffusing  , 1on the intensity of the light. The resistor is  sphere.
4l
                                                                                                                   I

Refer to the film instruction sheet to deter-
mine its correct DIN or ASA speed. The
appropriate speed is set against either the
DIN reference mark (7) or the ASA reference
mark (12). The scale may be turned by means
of the moulded ridges (13). A DIN/ASA con-
version table will be found on page 20.
                                                   5

Push the diffusing sphere completely to the  Move the acceptance-angle adjustment lever
right as far as it will go. Select the required  to 30o and centralize the diffusing sphere.
measuring angle, then aim the meter at the The meter is then directed from the subject
subject (as shown by the arrow in the pic-  position towards the camera a shown by the
ture).                                    arrow in the illustration.
             Refleeted
               Light
         Measurement
   tg


                              www.butkus.us

Measuiing





The green end of the rocker switch (3) is  reference lights to equal brightness,  it is an
pressed and the adjustment ring (4) is turned  indication that the light intensity is too low
until both reference lights (10) appear of  for the high intensity measuring scale and
equal brightness. At this point, the shutter  the procedure should be repeated but with a
speeds and aperture numbers lying adjacent  red side of the rocker switch depressed.  In
to each other on their respective scales offer  this case, however, there will be a red ex-,a choice of exposure combinations from  posure time scale opposite the aperture    I
which can be selected one suited to the  scale from which to choose the requiredsubject. lf it is impossible to bring the two  exposure combination.
                                                                                                         'l

Balancing the Reference
Lights





When the operating switch is depressed, one
or other of the reference lights will be weaker
than the other or may not light at all. The
disposition of the lights provides an indica-
tion of the direction in which the ring must
be turned to equalize their intensity.  lf the
left-hand light is the brighter, then the mea-
suring ring should be turned clockwise;  if the
right-hand light is brighter then the ring
should be turned anti-clockwise,   i. e. the top
of the dial is turned towards the dimmerwww.butkus.usof
the two lights.
8

The viewfinder of the POLYSIX-electronic
shows the subject and superimposes upon  it
the measuring fields for 30o, 20o and 10o.
The outer circle is, of course, the 30o field,
the middle the 20o and the inner the 10o.
In the window (B) can be seen the measuring
angle which has been selected by moving
the lever (4).
The smaller measuring angles allow precise
measurement of small areas. In fact, indi-
vidual parts of the subject can be measured
separately to establish the lighting contrast,
i. e. measurement of the lightest and darkest
parts of the subject. The contrast range
which the film can reproduce correctly is
dependent on its type and in the case of
negative films (black & white or colour) on
the characteristics of the printing paper or
print film to be used. In general work with
normal materials, contrast ratios in the ranqe
1:16 to 1:60 can be expected.

About the Batteries        Interpreting Exposure
                        Readings





The POLYSIX-electronic is powered by two
1.5 volt cells such as IEC-R6. Varta 28O or
244, or equivalent. The useful life of a set   It should be mentioned at this stage that the
of batteries under average use is about one TPOLYSIX-electronic  cannot think for you. In
year but if the reference lights begin to loose  the same way that a computer is helpless
brightness after a time, it is an indication  without the skilled interpretation of a pro-
that the batteries are becoming exhausted  grammer, so the POLYSIX-electronic  will
and should be renewed. To change the bat-  provide more precise exposure information
teries, open the battery compartment (16)  the more skilfully you use it. The lrrore    r
with a coin. Loss of voltage by the batterieswww.butkus.usexperience you gain with the POLYSIX-elec-does not cause inaccuracy of measurement.  tronic the easier  it will become.

II
   j
p





    It should be appreciated that the POLYSIX-
  electronic sees each subject as a varying  areas than "average" which could result in
  mixture of light, medium and dark areasl a false reading. In such cases, find an area
  which (when taking reflected light readings)' in the scene which is of average brightness
    it integrates into an "average" on which the and measure that. The variable acceptance
  exposure reading is based. This "average"  angle of the POLYSIX-electronic is a great
   is correct in a surprisingly large proportion  help in this sort of situation as it permits
   of cases but occasionally a subject may have more convenient "isolation" of the selected
  a much higher or lower proportion of dark area without influence by its surroundings.

a position which is receiving the same light
as the subject with the meter pointing back
along an imaginary axis parallel to that bet-
ween the camera and the subject. Altogether,
this is an extremely convenient method of
light measurement, particularly for outdoor
photographs for, very often, the camera
position receives the same light as the sub-
ject and it is only necessary to turn round
and take a reading in exactly the opposite
direction of the subject.
                                          13

Lighting for Effect





Many pictures are improved by deliberatelyltowards the fill-in light, can be made and
increasing or decreasing the lighting con- lcompared. With black & white film, the dif-
trast dramatically but contrast manipulation lference should not normally be greater than
                                                                                                       ofshould not be overdone -   if increased too lthe 1:3 while with colour film the readingmuch the film may not be able to cope. lf in lthe lightest side of the subject should not be
doubt, check the lighting contrast by measu- more than double that of the darkest.  lf it is
ring it; the POLYSIX-electronic is ideal when lwished to produce shadowless soft lighting,set at its narrowest angle of acceptance. for "high key" pictures or copying work, the
First, the shadow side, then the highlight lights should be arranged so that the POLY-
side of the subject may be measured and lSlX-electronic gives the same reading from
compared; alternatively, incident lightwww.butkus.usrea-lall parts of the subject, and background  (if
dings, first towards the effect light and then lany).

Sharpness in Motion
                       and Depth

f;

   After taking an exposure measurement, the  less depth of field. Alternatively, for a subject
    iris and shutter speed scales lie adjacent to  having great depth a small aperture should
   each other, for example, as shown below:   be chosen but a slow shutter speed will
                                                    result and the operator must guard against
                                                                                            a  f/stop 22 16 11 8 5,6 4  2,8  2   camera shake. The choice is very much                                             matter of personal experience, but in any   shutter
                      1                                        case you may find that there are hints in             /s 1/ts 1/to                                             1 /eo 1 /rzs 1/zso 1/soo 1/tooo  speeds                                         your camera instruction book, while many
                                         photographic text books give suggested
 li  trduilEach pairPail  Lrof aPt'laperturerulu   a1ilLrand u,\PUJursexposure time  shutter speeds for various types of subject
 J indicates correct overall exposure, but only and tables. In general, it can be assumed f one combination is likely to suit any  parti-  that sport scenes call for the fastest shutter
li cular photographic subject.                   times, while static landscapes can be taken
flFor instance, with a rapidly moving object, a with the longer exposure times, say t/eoth,rrhigh-shutter speed should be chosen but the  r/roth or even more if the camera is firmly
  correspondingly wide aperture will mean  supported on a tripod.
                                                                                           15

speed to freeze movement and small aper-
Very often the picture will require both near  ture to gain depth of field tend to diminish
and far objects to be equally sharp. Just how  the choice of exposure combination so that
much is indicated by the depth of field scale  usually there is little doubt as to which is to
of the camera lens or in a chart which may  be selected.
be included in the camera instruction book.  Occasionally the demands of the picture are
The smaller the aperture opening, the greater  such that a compromise must be chosen. A
the depth of sharpness will be but this ne-  slower than ideal shutter speed which risks
cessitates lengthening the exposurewww.butkus.ustime.  a little subject movement  is often better than
The conflicting demands of high shutter  not trying to get the picture at all.
16

Exposures at Night       Colourat Night





 lf you are photographing at night and wish
 to retain the character of night in the picture
 it is actually necessary to use shorter expo- At night, in the streets, shop windows and
 sure times than indicated by the POLYSIX-  illuminated advertisements make excellent
 electronic, for the meter will try to "correct"  photographs. For scenes which are predo-
 the exposure and make the picture look as  minantly  lit with neon or fluorescent lighting,
 though it had been taken in daytime.                it is best to use daylight typefilm. For scenes
 There are no set rules and only experiment which are predominantly  lit by incandescent
     personal experience can really help you. lamps it is best to use type A (artificial light),and
 The reaction of films to long exposure times  film. When in doubt, daylight type film is the
 is subject to certain changes and you should  best choice as it gives the most pleasant and
 refer to the discussion on Schwarzschild-  acceptable reproduction of colours under all
 effect (reciprocity failure) on page 22.         conditions.
                                                                                         17

In the Snow





Reflected Light Measurement
When using the reflected light method on  use incident light measurement  for this type
snow-covered landscapes, the entire reading  of subject. By incident light measurement, a
area is filled by brilliant white light. An  "straight" reading is usually the correct one
overall reading would generally be too high  for snow but if you wish to achieve special
to give detail in people or objects forming a  effects, e.g. to emphasize fine gradations of
small proportion of the scene. The variable shadow detail in the snow, then try half ormeasuring angle of the POLYSIX-electronic  one stop less. In this circumstan;,;il
will often permit selective readings to be  course, the foreground may be a little lacking   I
taken from the important part of thewww.butkus.ussnow-  in detail or may reproduce with rather satu-l
scape, but generally speaking,  it is better to  rated colours on colour film.
18

Cine Exposure


                                 The POLYSIX-electronic is as proficient at,
                                            reading exposures for cine as for still. Mea-f
                                         surements are taken in the usual way, either
                                                  reflected or incident light methods, and the,
                                              correct aperture setting is the one that lies  I
                                          adjacent to the "equivalent shutter speed".  I
                               The "equivalent shutter speed" at variousl
                                        running speeds (frames per second) willl
                                          often be quoted in the camera instruction   "
                                          manual, Oui it not they can be calculated byl
                                             the following method                                                           I
                                        Double the filming speed in f.p.s., then con-l
                                                   vert  it to a reciprocal. Then select the shutter
                                 speed on the POLYSIX-electronic scale    I
                                       which is closest to the resulting fraction aslg-{4u5 'u i                                           the "equivalent shutter speed"., e.g. 16 f.p.s.l
                                     doubled = 32. Reciprocal = 1/zz. Nearesti'2 '4 '8 etc. are fractions of seconds: 1/z -  shutter speed on scale = 1/zoth.                              I
      1/e sec. etc. Unmarked numerals 1 2 4 Some modern cameras actually have some-l1/r -
etc. are full seconds.                     what shorter equivalent shutter speeds than  I
1m 2m 4m etc. are minutes. th 2h are hours.  produced by the foregoing formula, but the

DIN    ASA         DIN    ASA      differences are seldom large enough to have                                    any practical significance.
 6          3      25      250     Note that in some cine cameras with reflexl 7          4      26      320      viewfinders, a proportion of the light enteringl
 B          5      27      400     the lens is diverted into the finder and there-
 9            28       500      fore the light reaching the film is less, aper-10                    6I      29       650     ture for aperture, than with a nonreflex;11         10      30      800     model. Check the camera instruction manual'
12         12      31      1000     for the actual correction which must be13         16      32      1250      allowed.
14         20      33     1600
15         25      34     2000
16         32      35     2500
17         40      36     3200
18         50      37     4000
19         64      38      5000    On the scales 7 and 12 of the POLYSIX-elec-20         80      39     6400      tronic, only the more importantASA and DIN21        100      40     8000    speeds are actually numbered. However,22        125      41     10000      intermediate speeds are marked and the23          160      42    12500                                                                                          chart                           www.butkus.usequivalent speeds are shown in the24         200                                 shown here.

lr.cr' nical Su pplement


 Diagram of the POLYSIX-electronic

 1  Battery                                            lll
 2 Transparent grey wedge                                                   lillnrr*-
 3 Cds photoconductive  cell
 4 Standard resistance
    Transistorized sum and difference
     amplifier
    Reference lamps

Pictures taken under very dim lighting con-
ditions require long exposure times (don't changed and corrections made with suitable
forget the tripod!). With all film types the  correction filters. The following charts have
so-called Schwarzschild (reciprocity failure)  been compiled from data supplied by the
effect may become apparent when exposure  actual film manufacturers and offer a good
times are abnormally long and the actual  basis for experiment for occasional "exis-
measured time may have to be increased to  ting" light work. lf much long-exposure worki
avoid under-exposure (but see page 16).  is done, it is well worthwhile obtaining thel
Different types of film are affected to a dif-  special leaflets from the manufacturers, and'
ferent extent and for this reason Reciprocity  applying to them for their recommendations
Effect cannot be taken into consideration on  on specific film batches. Do not overlook the
the scales of the POLYSIX-electronic. With  fact that when using calculation  filters theirl
colour films, not only will exposure timewww.butkus.usbe  factors must be added to the already leng-l
affected but colour balance may also be  thened exposure caused by reciprocity effec