Dejur Models 5B and 6A light meter User manual

NNGDETS
                         5B&6ff




"Duql Professionol" Exposure Meler
",Astocritic" Mode-l 5O-A Fxposure Meter
"Autocrilic" Model 5O-A "Cine" Erpa.-
    sure Meler
 Model 58 Exposure frlete?
"Versatile l"  12 1ro x 3!13l €nlorger
"Versalile ll"  13 !/,r r 4 rt I Enlorg*r
"Verqliie Proteerlorrerl" {4x51 €nlorgei'
"DeJur 8" Moiisn Pi<ture Proieelcr
                                  www.butkus.us

INSTR,UCTIONS FOR,
OPERATING THE

  DEJUR
  58A6A
PFIOTO ELECTRIC
EXPOSUR.E fNETERS

a highly sensitive electrical indicacing instru-            enr!1'. Each film, therefore, has an exlx)sure
 rnent; and a set of calculator dials. The photo-         jndex for davligl'rt and another for nrngsten
 electric ceil has the property of generating elec-          light  ( as the most frequently used artificial trical current under the influence of light im-            illuminarion  )  .pinging upon its surface. This current enters
rhe indicating instrument and clluses a deflec-
tion of the pointer. The extent of the pointer
deflection bears a fixed and precise relationship
ro the intensity of light falling upon the photo-electric cell. The pointer deflection is. there-            Ihe Cofeulotorfore, a measure of light intensity.   .4
                                            The calculator on the DeJur exposure meter
                                                                       is composed of a stationary and a movable dial.
 -h                                   Two sits of graduated divisions are etched on                                                             -such                                                                            position                                                                                                           divisions                                                                               that the                                                                               in                                                           dial                                                  t    each  .. )   FiIm Exposure  f ader                                                                      Thus                                                             be aligned.                                                                            dials can                                                   rwo                                          on the v                                                                                      the di-                                                           visions representing the light intensity on one
   Photographic 6lms differ in respecr to their           dial can be aligned with the divisions rePre-
sensitivity to light. Light of rhe same intensitr'          senting the exposure index on the other dial.
failine on various kinds of film u'ill produce
different photographic effects due ro the in-          The f-values and exposure times represented
herent characteristics of the film and the lighr        by scales of graduations on the two dials canto u'hich it  is exposed. These characteristics.       #   similarly -aligned. Thereby the calculatortherefore. must be taken into consideration ip          orovides a mechanical means for accurate cor'
determining the correct exposure.                                        I            relation of the four factors of film exposure   Iiilrns of different light  sensitivitl' are ag-           previously mentiond.
signed different exposure index numbers. Dalr-
light and artificial lighr affecr the 6lrn differ-

Thus, if your camera has a normal shutter
                                                       speed of 7/iO sec. and you want to photograph      Exposure lor Motion Picture         with a frame speed of 24, the applicable shut-
                                                                                     speed does      Cqmeros                                        rer speed is 1,':i5 sec. If the shutterE                                        not appear on the calculator, use the next
  Find the normal shutter speed of  yout         shorter exposure; in this case I /50 sec.
camera at 16 frames per second. Most amareur        The correct diaphragm opening will be in-motion picture cameras have a shutter speed of        dicated by. the f-value aligned with selected 1,/30 second at 16 frames per second. Since the        exposure ume.shutter speed is proportional to the frames per
second, the following relation berween frime
speed and shutter speed will show:                                         1,a                       SHTITTER                                                                             Fillers     FRAME SI'EED                        SPEED              tv    Correcfion tor
                                                                                                            the     8 frames per second     l/1,  sec.         A photographic filter prevents a part of                                                                                                   camera.    r6 frames per second     1/30 sec.             original'I'he intensitylightoffromlight passingindicatedintoby thetheexposurc    24 frames per second    l/45 sec.           merer will be greater than the intensity of
                                                                                                Conse-    7) frames per second    l/6O sec.            rhe filtered light entering the camera.                                                                                                                       light                                                                                                     filtered                                                                      exposure                                                                                    for                                                       the correct   48 frames per second    1/90 sec.            quently                                                                                                            the                                                                         shown                                                                                 by                                                                 than                                                                         the exposure                                                           witt be greater     (t1 framcs per second     l/l2o  sec.             calculator for unfiltered light.
  To get the motion picture exposure, apply the        The ratio of the exposure for filtered light
exposure index on the calculator in the usual        to the exposure for unfiltered light is calledmanner. Select the best exposure-diaphragm          rhe filter factor.
combination by using the shutter speed cor-          T'he filter factor depends upon the nanrteresponding to the frame speed of the camera.                ( color) of the filter, the quality of the light
                       16                                                L7

and thi sensitivity of the film. All three condi-        developer. By measuring the light transrnitted
 tions must be known ro determine the appro-       by other negatives, )ou can cornpute the print- priate filrer factor. The facror usuaily per-       ing time required for these other negatives
 manently marked on rhe filter-mount is, there-     when using the same rype of paper and fore, likely to be inaccurate for different films
 and under varying conditions.                               cleveloper.
  When using filters, consult a reliable table         Care must be exercised in measuring the
  lc.rr the appropriate lilter facror for the specific         light transmittecl by the negative in sr"rch a way
 lilm and lilter 1'ou are using. Then determine       as to obtain at:erage ligl:t readings represenra- the exp<.rsure for unfiltered ligtrt in the usuili        rive of the orerull densiry of tlie negative. nlanner and multiply by the filrer factor ro
 obtain rhe exposure for the filtered light.              In contact printing, place the exposure me.er
                                                                                                            conracr  k must be remembered thar tilter factor        in such position that tbe light from the rables are nor to be regarded as being complete-       printer passes through the  neglative before
 ly accurate. They will serve, however, as a        reaching the merer.
 rough guide upon which ro base initial ex- posures.                                              In projection printins, holcl tl"re meter cither
                                                       in the plane of tire printing paper or at tlre
                                                         lens of the enlarger, so that the enlarger light
       Use of Erposure !n Printlns       hcld et the lens. a different standard q'ill haveI 0                                              passes through the negative. If  tlre lnetet  i:   The DeJur exposure merer can be used as an       ro be estabiished for various distances from
 aid in contac or projection printing. First de-        lens tt-r paper.
 termine by experirnent. the best printing time
 for a negative r*'hich wiil be used as your          Adjusc the calcuiaror     rhar the 800 blori;
 standard rvith a particular grade of paper and      on the "Exposure Index   scale is aligned n'iih
                     18                    www.butkus.us 10
                                                                                                                                                                                                                                                                                                                       iII                    .,

..DUAL       PROFESSIONAL'' EXPOSURE METER
                o
"AUTOCRITIC" MODET 5O.A METER
                 O
..AUTOCRITIC''            MODEL 50-A "CINE"
   EXPOSURE METER
                o
IAODET 58 EXPOSURE
                  o  'YIETER
"VERSATIIE l"  121/q x 3r/al ENLARGER
                o
"VERSATILE  ll"                     (3 % x 41/al ENTARGER
                 o
"DEJUR PROFESSIONAL" (4 x 5l
  ENIARGER O
"DEJUR 8''         PICTURE PROJECTOR
            'I,IOTION
F 540. LDXOX - 7-49 .KE      PTD. IN U.S.A.