Hasselblad Automatic Diaphragm User manual

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into aircraf't, for example, need no modi-   lens always have the same angle of view.
fication.                  A blue silicon photocell is the measure-
                                    ment cor:nponent in the di'aphragm control
Description                                 unit. The biggest advantage of a si,licon
Film speed is set on the unit, and a shut-    cell, compared to a CdS cell, is the former's
ter speed is chosen appropriate to the sub-   fast reaction time. The si,licon photocell
ject. The unit can accommodate film    is also practically inertialess, resulting in
speeds from 25-1600 ASA (15-33 DIN).   extremely rapid response to variations in
Light entering the unit's photocell acts on   light intensity (a sweep from f/2.8 to f/22
a control system governing the operation    in about 1 s). The silicon cell a,lso responds
of a servo motor which rotates the lens   with great accuracy even when light lev-
diaphragm ring to the correct f/stop.        els are very low. The spectral sensitivity
The acceptance angle of the control uni't's    of the silicon cell is largely the same as the
photocell is the same as the angular field   spectral sensitivity of the human eye and
of the lens. Thus, the photocell and the   of common film emulsions.

The reading of extreme,ly rapid fluctuations    Light intertsity varies considerably in the course
in lightintensity around a meanvalue, as in    ol a day. So you may have to guess at an average                                                       value for exposure  il changes in exposure settingsfluorescent tube illumination, is"smoothed    are impossible or inconvenient. Thus, un auto-
away" by the automatic diaphragm con-     ntcrtic cliaphragm cctntrol unit is a must lor the
tr'ol unit so that a slable f/stop value is ob-     v,ildlile photographer operating his camera by
tained and current consumption is ,mini-    renlote conlrol with a cord or radio.                                   A 5008L/M, triggerecl by radio, litted with amized.                                        Magazine 70 to keep ntogafine chonges to a ntini-
The automatic diaphragm control unit is       trttrrrt and ct 250rnnt Sonnur with an eLttotttatic
designecl for use in ambient temperatures    cliaphrugnt control tutit rttouttted, was usecl lor this
                                                                                                                                                                                                                                                                     ,s.from + 122oF to -4oF.                            sequence.The photographThe shuttet'at the hereleft waswas takenpreset earlyat l/500inA recl warning lamp lights on the left side     tlrc rnorning when the sun was low on the
of the automatic diaphragm control unit    horizon and the eider still in shadow. Bur a
                                                      well-exposed lrame was obtained anyway, tlnnk.rwhen an f/stop is called for outside the                                                        to the automatic diaphragnt control unit.range of the lens used.                                              The photograph at tlte right was tuken later in theExposure compensation when extension    duy when the nest waslully illuntinated by the sun.

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tubes or filters are used can be attained bv     Tlte monitoring and registration ol dillerent
                                                    processes with the aid ol a camera are becomingchanging the film speecl.                                                        increosingly comnlon. In many scientilic stud-
Battery drain                                                 i€s,irttervttlsan unmannedover o longcanTeraperiodis oltriggeredtime soatasregularto
                                                                     rec'rtrd a coLrrse of events. The quality ol theThe servo motor in the automatic dia-                                                        irnages                                                           obtained                                                                     ntay                                                                                                   vital                                                                                   importance.                                                                  be olphragm control unit is powered by the                                                      given                                                                       never                                                                                     repeated.                                   A                                                                        evetlt tnay                                                                      be                                                                                         This cir-
camera battery when the unit is used with    crutlslence rnakes an automotic diaphragm con-
the 500EL/M. At rest the unit consumes     Irol unit indispensable in such applications.
about 20 mA (a fully charged battery lasts   A 500EL/M can be lelt on its own to record
                                                                    itttuge af ter itttnge withotrt huntan supervision.about 24 hours). Current consumption dur-                                                           Tlte cliaphragnt is cluickly adjusted to changesing cliaphragm regulation rises to about        irt liglrt intensity. A corttmand unit can be used
150 mA (a battery then lasts about 3 hrs     wltert ct process ntust be sintultaneously docu-
during continuous regr.rlation). Each 500    ntented with dillerent canleras litted with diller-
ELiM battery has a capacity of 500 mA     entttlsiorts.ertt lenses orAnliltersB0trtrrtandPlatnrloadedandwithl50mmdillerentSonnarlilnr
with a l0-hr discharse time.                         v,ere used on the cotneras in the photograph.

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                                                                  F'light tinte is expensive so aerial photogrophy;rrr"-"*ou,r.r,  compartm ent 2rs avail-                                                 has to be as ellicient as possible. A steady holdable and is attached to the camera accessory                                            on the canlera is e.tpecially vital to the aerial
shoe when the automatic diaphragm con-    photographer, who has to work in a vibrating
trol unit is used with the 500C/M. The bat-    luselage. The double handgrip is especially
                                                    designed to provide such a hold plus enhancedtery for battery compartment 2 can be                                                                stability. The pltotographer has here modilied hischarged in this compartment using a Has-                                                 double handgrip for use with two 500EL/M's atselblad recharge unit I or III.                      the sume time. Automatic diaphragm control
The battery for battery compartment 2 has    units are erlmost inrlispensuble when ntore thun
a rating of 225 mAh.                           one c'(tntere is used nt tlte .same tinte. The photog-
                                                   rapher is then able to concentrate on his sub-
The lens diaphragm can a'lso be set manu-    ject and can make one exposure alter etnother
ally when automati,c operation is turned    without removing his eye  f ront the viewlincler,
off. F/stops can be read off on the base of    the diaphragnt control unit aulotnaticnlly settirtg
the lens barrel.                                        the correct l/.stop. Every lrutrte is properly
A multiple connector must be emp'loyed    lightingexposed,whicltde,spitecunthebewideencoLuttererlvuriatiort.sduringin    ueriul
if the camera is to be used unmanned and    photography.

www.butkus.ustriggered by radio or release cord. The
multiple connector 'makes two simulta-
neous connections possible.





Rapid events in the arena can be covered ellec-
tively with a Hasselblad 5008L/M. A photog-
rapher lorced to make lrequent changes in ex-
posure settings during shilting lighting condi-
tions may ntiss important shots. A situation
made to order lor the automatic diaphragm
control unit! It automatically keep.r exposures
right on the nose. The photograplter can tlten
concentrate on his subject and lire away at the
appropriate moment. An automatic diaphragm
control unit therelore produces a greater pro-
portion ol accurately exposed lrames than would
otherwise be possible. The sequence shown here
was taken using a Hasselblad 5008L/M litted
with a Magazine 70 loaded with Ektachrome MS
film. The automatic diaphragm unit litted to the
250ntm Sonnar lens used.
Photo: Jens Karlsson