Gossen PROFI-Spot User manual

Lens
           Beam splitter mirror which divides the
                  light into a measuring beam (-)
            and a view  f inder beam (- - - --)
           3  Collective lens
           4  Reversal mirror for ineasuring beam
            5   Light entranoe aperture of the
             PROFISIX
              6, 7, 8 Reversal mirror for view finder
            beam
       9  Reversa! lens for view finder beam
      10 View finder rings with LED readout'
      11 View finder ocular
      12 Apertures for adjusting measuring
              ang le





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General indications
                                                                                                          -10"
For even greater selectivity the PROFI-spot attachment Jor
the PROFISIX provides not oniy 10o and 50 but, in addition
a 1o angle for ultra precise exposure measurement' Once theattachment is connected to the PROFISIX it automatically
adjusts the meter sensitivity. The small measuring anglespei'mit precise viewing and taking readings of even the
imallest detail of the scene, thus ensuring maximum accuracy'
Because of its extremely high sensitivity the PROFISIX will
cope with most of the job requirem-ents -  even with verydifiicult light situations. The single reflex lens design permits
measuring- and viewing through the same lens eliminating
parallax problems; the light beam is split inside the PROFI-
bpot into-a measuring beam and a viewing beam (see illus-
tration page 1).
The proven advantages selective readings of specificsubje6t various, greater creative possibilities, top qualitypictures are appreciated and enjoyed both by top pro-
iessionals and demanding amateur photographers'

Attaching to the meter
      Remove deiachable front shield (33)
        covering the accessory jacks from the
       PROFISIX. Put the hemispherical  dif-
        fusor (1) at the right, align the PROFI-
      'spot attachment so that the plugs on
       the attachment are opposite the jacks
       in the meter and the recess in the
       attachment opposite the hemisphere.
       By holding the PROFI-spot by its ribbed
       side (46) push the accessory straight
      on to the meter. When attached to the
      meter the PROFI-spot automatically
         ad justs the meter sensitivity i.e. the
        loss of light caused in the PROFI-spot
         will thus be compensated and this in
          relation to the measuring angle selected.




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Thread the safety line that comes  with the PROFI-spot through the eyelet (99)
at the PROFI-spot and attach the metal hook at the other end to the carrying
cord of the PROFISIX meter. This will make handling the combination .PROFISIX
plus PROFI-spot safer and easier.

Technical data
          ' Measuring circuits for 1o,50 and 10o   visible in the view finder
      Readout of the selected angle:         with LEDS in the view finder
  _   Full visible area:                       approx. l5o
   .    Sensitivity at 18 DIN and
     .        measuring angle 'l0o        EV                                                   -3... +16            measuring angle 50        EV -1 ... +16            measuring angle 10         EV +2... +16
     Maximum sensitivity at            15  18  21  24   27 DIN     ,   ,andmeasuringangle 10         1   2   g   4   SEV
                                                                 2 EV            measuring angle 50          -2   -1   0   1                                                           EV            measuring angle 10o          -4   -3   -2   -1    0
       Correction factors when changing
             the angle                       are automatically adjusted for
       Light beams                               split beam optics, free from
                                                    parallax error
.      Distance range                         0.5 m .. . e      ,       with additional lens (2 diopters) 0.2 m ..  . 0.5 m
              (auailable at your photo. dealer's;                                LuJ ku 6, t/ 6                  filter thread O 35.5 mm)
      View finder ocular with diopter
       correction for adjustment to the
       viewer's eye                              www.butkus.usby *2.8 to -4 diopters
                                                                                  s

Operating procedure
set the film speed at the PROFISIX according to the PROFISIX manual. Connect
the PROFI-spot to the PROFISIX. Point the PROFI-spot at the subject to be
measured and look through the view finder. You will see there the three rings
   for 1o, 50 and 1Oo respectively. Turn the selector (94) to the appropriate
setting. Red digits at the upper edge of the view finder will show you the
measuring angle chosen. Thus the measuring angle selected will stay visible
in the finder while the reading is being taken.
Point the PROFI-spot at the subject to be measured and activate the PROFISIX
by pressing the measuring button (6).After you release the button (6) the
reaciing of the subject area measured is made and electronically stored in the
meter. Now while looking at the meter rotate the computer ring until the meter
nulls. Read any combination of f/stops/shutter speeds you desire from the
calculator dial and set them at your camera; no additional calculations or
corrections will be necessary at all.'Exposure factors due to filters or bellow
extensions can be programmed into the PROFISIX with the EV modification
setting (15) on the PROFISIX computer ring (24\, iust as you would do it whenmeasuring with the PROFISIX alone. The corresponding instructions in the
PROFISIX manual are applicable also for the combined unit PROFISIX + PROFI-
spot.

Taking a reading at low light levels
           When taking readings frequently at
             very low light levels you should
                attach the sticker enclosed with the
               PROFI-spot to the unit as shown in
                  this illustration. The table shows the
            maximum sensitivities for the indi-
                vidual measuring angles, these be-
               ing the minimum light levels below
              which the readings of the PROFISIX
             would no Ionger be valid. This very
           same table is also shown on the
              back of the PROF|-spot.





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Helpful hints
The measuring angles of 1o,50 and 10o you can preselect will normally meet
any photographer's requirements. Precise exposure readings as obtained with
the PROFI-spot will only be of use to you when applied correctly to your personal
technique of taking pictures. The following factors will have an influence:
1. the scene brightness range (the difference in contrast between areas of
   high light and shadow in the subject area)
2. the type of film used (negative or transparency film) and their recording
     ability
3. the resulting gradation of the combination of film and developer
These three influencing factors are to a large extent interdependent. In Some
subjects you can change the scene brightness (the areas of high light and
shadow) -  but this is impossible when photographing subjects illuminated bydaylight only. Lights and shadows are a natural phenomenon which can be
changed to a certain extent by using reflector surfaces. When photographing
subjects illuminated with artif icial lights, the differences in contrast can be
controlled by changing lamps and lights.
All films have a characteristic response to exposure and developing processes.
This can be seen from the characteristic gradation curve. A certain control can
be effected through the developing process. We refer you in this regard to the
special literature available, because we cannot include all of it in this manual.

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Scene brightness range
Only when knowing the scene brightness range you will be able to take precise
exposure readings. The brightness contrast of a subject is the difference between
the exposure data measured at the lightest and at the darkest important area
of the subject which are to be recorded with sufficient detail in the photo. The
contrast ratio is thus the difference between these two readings expressed in
EVs or f/stops. With relatively small contrast ratios it is of no importance  in
which portion of the straight line section of the gradation curve the blackening
will occur when considering reproduction of contrast. Exposure will get more
important the bigger the contrast ratio is. When trying to obtain optimum values
as to differentiation of detail and grain size, the lowest possible exposure should
be used. Shorter exposure will normally increase the recording capability of your
film. A correctly exposed negative wilt show slight but still recognizaSte  d-etail
in the shadow area'                              l!;      . ,.   ,   , v.                                              -t





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                                                                                            11

The following general rules apply when measuring the scene brightness range:
1. Negative films
      lf the contrast between the bright and the dark areas does not exceed 3 EVs,    all of the intermediate values can be used as setting values. lt is true, sig-
   nificantdifferenceswillchange  the density of thenegative,which  will influence
   the exposure time when englarging, but in most cases acceptable pictures
   will be obtained. Negatives of higher density will produce not such good
   reproduction of outline while showing the grain more clearly. Under these
   circumstances best detail recording will be obtained when working in the
   lower third of the range. When having obtained a difference in the values
   measured of p.e. f/stop t/4... f/11, choose therefore f/8.
    ff the readings for the bright and the shadow areas are within 2 EV, you will   get better relults when using shorter exposure under these conditions. At a
   given difference of p.e. t/4...t/8,  this would be f/8'
      lf your readings for the important high light and shadow areas differ by more
   thin 3 EVs, more ample exposure will have to be applied. With a difference
   of 4 EVs, the setting should be approx. in the middle; with a difference of
   5 EVs a value in the upper third should.-be chosen. Still greater contrast ratios
   can be coped with only by using special developing processes.





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2. Transparency  film
  As compared to the negative film the transparency film can cope with a
   greater scene brightness range, however, the exposure range that can actually
  be used is smaller. This applies also to subjects having ho outspoken con-   trasts in brightness. This is also the reason why even slight changes in
   exposure cause significantly different transparencies.
 '  Measuring the scene brightness range of the subject will enable you to
   decide whether that subject can be truly recorded in the photo under the
   given lighting conditions. In this case note: the higher the scene brightness
   contrasts, the shorter the exposure in order to avoid Washed-out -colours   in the high light areas.





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                                                                             13

Your PROFI-spot is a valuable precision unit, made with great care and accurately
calibrated. lt deserves your good care! lf repair or adjustment should ever
become necessary, send your PROFI-spot, carefully packed to

           GOSSEN GMBH
                 Servicestelle B
                Ndgelsbachstrasse 25
              D-8520 Erlangen

or to the GOSSEN agency in your own country.



To expedite handling please send yur PROFI-spot only -  wlthout case or cordor any olher accessories.



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