BERTRAM AMATEUR User manual

Generol Observotions.
With the Bertrom AMATEUR meter the photo-
gropher is in o posilion to get occurotg
light reodings lrom o sturdy ond servic{bterlslrument. A corrying strop will be fo-unU
rlrost convenient 1or one-hond operotion.
Alternotively the Bertrom AMATEUR con b€
mounted on o wrist strop to whicfr il  isottoched by meons of o boyonet   f itting.
A neck strop is olso ovoiloble on requesl
through good photogrophic d6olers.
Although the Bertrom AMATEUR is shod-
prool to o remorkoble degree, cor€less
treotment con domoge the instrument.ln sudl,.
coses o good photogrophjc deoler strout&be consulted. He will usuolly be oble to
orronge for repoir ot the meter by o relioble     .
trode rcpoite(, ot in extremg cofes moy.,orronge for its return to the monutoc
fol repoir.
          Ernrl & Wllholm Btrlrom
  Fqctoly of photo technicul noosuring inslrunrnls
         Munich- Posing
                                         IPrinted in Germony      Nr. 43
 t

A Protective shutter
  B Scole of light volues
  C Pointer
   D . Lens opertures
  E Exposure times
  F Slot of lighr volue
         (set   f or 11 )
  G Button of rototing disc
                                 f or  f ilm speed settingI
     t  Film speed sfole,    t  Rototing disc'
        for Inserting llght volues
  X Corrying strop slot

l'riD

                             ll. How to toke
               o Reoding
 @
         tr rft1,-"os

Point the AMATEUR ot the subject.
The viewing ongle is 500. Then turn
Rototing Disc I until the light volue
reoding oppeors in the upper window
F. lt is now possible to reod olf the
correct operture ond exposure time
lrom scole D in relotion to scole E.
In the exomple given the light volue
is 12.

l. Film Speed.
           The rototing disc
              shown in Fig. 2 is set
                 occord. to the speed
                                                                        f ilm being             of the
             used (DlN, SCH0 or
                ASA/BSl). The pro-
lective cover of the photo cell is
opened by meons of o pushing mo-
vement of the thumb olong the side
of the instrument. Core should be
token thot the cover is opened to
its   f ull extent ond is in no woy
obstructed whilst reodings ore being
token.

Cine
toble

4
                                                                          I
                                                                                               rt
                                                                                                                    l.

lll. Aperture ond
            Exposure Times.





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    Figure 5 shows the exposures for o firm   with o sp-eed of                            18/ro DIN when the light   volue is ll.   lt will be seen thol the lens
    operture wculd be l/5.6 lor o shutter speed         r/:oo.h                  pointer                            indicottng                lf the                                                     light                                 the   -of'volueb            between                                     f ell                                                      inier-                     l0                   ond  I l, tne
   mediote settinq ot I/6.3 for o shutter speed
                r/so ond t/ss Second indicoles tneIi 'betweenol tlrcr would be obtoined. The orrow heodr   lens operture when using o cine comero   running ot the normol speed of l6 fromes
   Per second.
   The cine loble ot Figure 3 shows the equi-
   volent exposures when running ot speeds
   other thon lhe normol 16  f romes per second.
  6,
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