Aplex Bellox Jr User manual

How To Use
          1.  Straighten the flexible sca[e shaft and tighten it at the rear
         clamp by turning it clockwise.
          2.  Loosen the ..t"* @ before mounting the camera and when                                                                screw.           rightly mounted stabilize it by tightening this
         3.  Bellows will be expanded easily with turning the knob @ clo-
         ckwise and can be fastened with left hand stopper firmly'
      Photography With The Bellox
        TheBellox'sfunctionistoprovideanadditionalamountofex-
       tension between the lens and the camerabody'
                                                                 close up           It effectively replaces the use of extension tubes for                                                                           so      photography or photomicrography, it eliminate the need for
       called macro lenses for larger-than'life-size-negatives.
                                                                            a      The Bellox is more versatile than either of these method fot
     number of reason. First, it provide a method of continuous focus-
      ing without the bother of enterchanging extension tubes of vari-
      ous length.                                        ?
        Second, it permit any intermediate ratio of magnification with-                                                                 rack.      in the focusing range of extreme close up to infinity by
      andpinionadjustment.Third'itismoreconvenientbecausethe.

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re are no gaps or dead areas in the focusing range.
  The Bellox is attached directly between the camera and the
camera lens.
   It can be used in conjunction with normal, and the telephoto or,
wide angle lenses according to the role it is required to perform.
   It serves to replaces the helical focusing mount of the lens
with its'own precisely calibrated engraved focusing racks.
  Bellox is truely a photographic tool of unlimited use and scope.
  General Rules
  The further the bellows are extended and the shorte'r the focal
length used, the greater is the image scale on the negative.
As the image scale increases, the depth of focus decreases. This
must often be compensated by applying the following maxim:
The smaller the aperture, the greater the depth of focus.
  Reducing the aperture requires longer times; and the excessive
                                                     meansextension in the case of close range photographs also
                                                                     aloss of light. If, for example, f./!l  is used, this figure has
meaning only for calculating the depth of focus      it no long-                                                      -                                                                    theer gives information on the strength of illumination. So
         time must be further increased"*por,rr"  The greater the image scale, the greater the importance of

evert millimetre of movement in any dircetion    not only in                          Jl                                                       -depth but also in  respect of containing the image within the                                     'l'
limits of the filmframe. Thus a very slight movement may
result in the object being displaced on the film.
  When using very long focal lengths and at full extension it
may happen that the corners of the frame are not exposed.
  This vignetting, which normally has no particularly disturbing
effect, is inevitable in such cases, owing to the narrow aper-
ture in the camera housing
  Exposure
  Exposure is determined by the proper combination of shutter-
 speed and f (diaphragm) stop. The shutter speed, of course, r€-
mains unchanged by the addition of the Bellox, but the f  value
varies with the amount of bellows extension. The f value of a
lens is calibratid, and is completely accurate only when the
lens is focused at infinity. In normal camera use the error in
the f stop resulting from the extension of the lens when focused
at distances closer than infinity can be ignored since it is minor
and is well within the range of the film's latitude.
  With a bellows unit the lens is extended beyond the point at
which exposure compensation can be neglected, making it nece-

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ssary to apply the proper exposure correction factor. The fottow-
ing tables show the exposure factors f.or the most commonly
used lenses and are self-explanatory. The required exposure
increase (exposure factor) is applied in the same manner as a fi
Iter factor. Thus, a factor of. 2 requires one f stop larger open-
ing or half the shutter speed; 4 x  f.actot requires two stops co'
rrection; and an 8 x factor requires a three stop correction.
  Exposure compensation can also be computed by determining
the Effective f Value as contrasted to the Indicated f Value.
 ' The general formula is:
                                          Focal Length
  Effcctive f Value:Indicated  f Value x +EXTENSION
                                         Focal Length
Exampls; With a 50 mm lens and a bellows extension of
     50 mm, and an f8 setting, the true or effective f
..   stop is:Ef :8xjq+_q
         :8 x z                                           frrtt/,tJ.
  Therefore the actual f8 setting is equivaleut to f16 and it  is
necessary to determine the proper shutter speed for f16 rather
than f8. Simply read the shutter speed setting opposite fl6  on

B.

yonr exposure meter and you will have automatically corrected
for the required 4 x exposure increase which the charts indicate
for tbis example.
  When using synchronized flash: All manual operations must be
carried out before focusing on the object. First choose lens
and extension according to the size of the object and stop down
aperture accordingly. The flash reflector is best placed in front,
next to the lens Thus, in the case of full extension, the source
of light is extremely close, and conversely, when the bellows
are only slightly extended the reflector is  correspondingly
further away from the object. Once established, the aperture
always remains the same for the closer the object is appro-
ached the greater ia the extension and the smaller is  the
amount of light on the negative. At the same time, however,
this reduces the distance between flashlight and object thus
compensating the loss of light by the greater proximity of the
flashlight. When satisfied in respect of definition and position
of the image on the focusing screen, the exposure should be made.
And now hope you will enjoy your Bellox equipment.
  lllore than any other apparatus this equipment guarantees
succeSs.
                                          PRINTED IN JAPAN

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