Bronica ETR Auto Ext Tubes E User manual

The Automatic Extension Tube-E has been
       developed for the purpose of providing greater
        lens extensions than possible with the unaided
      Zenzanon E lenses (from 40 mm to 250 mm
       focal lengths), without loss of the automatic
        lens diaphragm and electronic shutter actions in
       the lenses. Thus, operations are identical to that
      without the automatic extension tube which
      means that operations are very simple and
        trouble-free even when the accessory is used
       between Zenzanon lens and ETR body.
       Three automatic extension tubes are available,
       with extensions of 14mm, 28mm and 42mm
       which are designated E-1 4, E-28 and E-42. For
        extensions greater than 42mm, the use of the
      Automatic Bellows Attachment-E is recom-
      mended because it can provide greater, variable
        lens extension.


@

www.butkus.us


   Finally, for greater pleasure and freedom from
  troublesome exposure calculations, the use of
  the AE Finder-E is recommended because com-
  plete exposure automation is retained even
  when the automatic extension tube is used.
   Please read the instructions through completely
  before you use the accessory, as you will then
  be able to use the accessory with greater ease
  and more satisfaction.





lmportant

The automatic extension tube-E can only be used singly.
Do not connect the automatic extonsion tubes to each other.
                               e

www.butkus.us

Nomenclature                      6
Attachment of Lens to Automatic
   Extension Tube                         I
Attachment to the Body               10
Detachment from the Body             12
Detachment of Lens from Automatic
   Extension Tube                     13
Care and Maintenance              15
Pointers for Close-Up Photography   16
Formulas for Macrophotography  . .       18
Close-Up Working Datas              20




                             o

www.butkus.us


Rear surface (Body side)


        Contact points




                                 Greencolored dot



                                         ng pins


                www.butkus.us

Locking pin   Lens release button
                              o

Mike Butkus  DigitallyDN:org,Date:cn=Mikeemail=mike@butkus.org,2026.04.20signedButkus,by21:55:03Mikeo, ou=Butkus.Butkus-04'00'c=US





                                 * The lens and/or auto-        (1 l First, check whether
        the cocking pins of the      matic extension tube
      automatic extension      cannot be  attached
        tube and lens are coin-      when the cocking pins
       cided to their green-      are not coincided to
        colored dots, if  not,          their green-colored dots.
        coincide the pins to
         their dots, by rotating
       them with your finger.




@

www.butkus.us





(2) Next, line up the red      When the lens is insert-
  dots on the lens and        ed, the locking pin on
  automatic extension        the rear surface of the   tube (front end), insert        accessory will extend
   the lens fully into the       an additional 2mm or
   latter's mount and,        so but will retract to its
  when  well   seated,       former height, when
   rotate the lens in the      the  lens is  rotated
   counter-clockwise di-        counter+lockwise  and
   rection until  it  stops         locked securely.  (about 34o). There            lf the locking pin does
  should be an audible       not retract, after ex-
   click which will indi-        tending 2mm, the lens
   cate that the lens is         is not securely locked
   securely locked.                in place, Therefore, re-  o

verse the lens back to     (1)The lens connected to
      the red dot position       the automatic exten-
     and then revolve  it       sion tube cannot be
       once more until it locks        attached to the body
        securely which can be         (or detached from the
         conf irmed by   the       body) unless the shut-
        height of the locking         ter is cocked, as in the
          pin.                     case for  attachment/
                               removal of the lens    *   lt will not be possible       only (see page 15 of
        to attach the automatic        the instructions for the
        extension tube to the        ETR}.
      body if the locking pin        ln other words, first,
        does not retract.                rotate the film winding
@                                   crank and cock the lens

www.butkus.us





                                    www.butkus.us

shutter. Next, line up     Preparations for  taking
the red dots on the    pictures are  completed
body and the automatic     with the above.
extension tube. Then.
insert the automatic ex-
tension tube fully into
the body mount. When
well seated, rotate in
the  counter-clockwise
fully until it stops. An
audible click should be
heard which will indi-
cate that the accessory
is securely locked into
place.                          o

I





      (1)The combination of       the lens release button
           lens and automatic ex-       (on the body) 45o in
           tension tube must, first,        the clockwise direction
        be detached from the      and then depress the
          body.                    lens release button.       * Do not detach the lens          Finally, rotate the auto-
         from the automatic ex-        matic extension tube in
        tension tube   first.        the clockwise direction,
                                     while keeping the but-
          Therefore,  first, rotate      ton depressed at the
          the film winding crank       same time, until a full
         and cock the lens shut-       stop is made at which
          ter. Next, rotate the       point the lens can be
          milled locking ring on        detached.
 @

www.butkus.us





                                    www.butkus.us
(1)The cocking pins on      (2) Next. depress the lens
  the automatic exten-        release button on the
   sion tube will be shifted       accessory and rotate
   slightly in the direc-       the lens in the clock-
   tion of release, when      wise direction (while
   the lens and accessory       maintaining pressure
  combination is   de-     on the button). When
   tached from the body.      a full stop is made, the
  Therefore, shift  the         lens can be detached.
   cocking pins to coin-
  cide with the green-
   colored dot, as initially
  done before attach-
   ment-
                             @

"   lt will not be possible
        to depress the lens re-
         lease button, when the
       cocking pins are not
        coincided to the green-
        colored dot and, there-
        fore,  it  will not be
         possible to detach the
           lens, too.




@

www.butkus.us

(1)The contact points on     (2)Always cover the front
  the  front and  rear       and rear surfaces with
   surfaces of the acces-         their caps to protect
  sory must always be        the contact points and
  clean, as  otherwise,         pins from damage and/
   there will be faulty con-       or dust during storage
   tact upon attachment        or when carrying them
   which might cause trou-         around.
   bles in shutter opera-
   tion,  f lash sychroniza-
   tion and/or automatic
   exposure control.





                                  G

(1) Focusing with the split-     (3)When using the 40mm
      image or  microprism        and 50 mm focal length
      spot may be lound         lenses,  it  should be
         rather difficult in close-        noted that there will be
      up shooting because of       certain magnifications
       a decrease in the actual         and/or exposure factors
        brightness through the       between the E-14 and
        lens, as will be ex-        E-28 tubes and between
         plained later. Therefore,        the E-28and E-42 tubes
       in such cases, focus       which  it  will not be
       with the matte screen         possible to use, because
         area.                          of the limitations in the
     Or  focusing screens      amount of  extension      with a central matte          possible with the helical
         area, such as the matte       focusing systems of
       focusing Screen-E or         these two lenses.
        Grid Focusing Screen-E
        should be used.            (4)The depth of field will
                             become more shallow
       (2) When using the 25O mm        as the magnification  is
        focal length lens, there        increased in  close-up
      may be some darkening       shooting. Therefore,       in the corners of the       focus as carefully as
      frame area. of about        possible and, at the
        2 mm or so.               same time, stop down
                              the lens as much as
                                       possible in order to in-
@

www.butkus.us

crease the depth of       photographer and/or
field.                        camera and that special
And, naturally, a slow        care must be exercised
shutter speed will be        for properly illuminat-
the rule, in this case.         ing the subject. A lens
Therefore, use a strong,         of a longer focal length
rugged tripod for hold-       can be utilized, in this
ing the camera set-up,        case, as it will permit
in order to eliminate       the photographer and/
camera vibration and,       or camera to be posi-
at the same time, use a        tioned at a greater dis-
cable release as much as        tance from the subiect
possible.                and the illumination.
At the same time. it     On the other hand, of
should be noted that in        course, the depth of
close-up shooting. there          field will be even more
is danger of a shadow        shallow which will re-
being case on the sub-         quire even more care in
ject matter by  the          focusing.





                                                              C)

The close-up working datas       is a small amount of exten-
       for the various lenses which    sion when the lens  is
     can be used with the auto-     focused on a near subject
     matic extension tubes are    with its helical focusing
      to be found in the tables in     system, too, but this can
      the following section.          be disregarded for all prac-
      Magnification is the rela-       tical purposes.)
      tionship between the size    The following table shows
     of the subject and the size     the increase that must be
     of the image on the film    made in the aperture or
     and is found by the follow.     shutter speed for obtaining
       ing formula:-           a correct exposure with
                                       these exposure factors.       ..__-!r!^_-!_      Magnrtrcatron_= lmage size                oE;t  rirc
     Exposure factor is the
    amount by which the F/
     number or exposure must
    be increased to take into
     account the decrease in
       light with extension of the
      lens because less light will
       fall on the film plane when
     the lens is extended with
    the automatic extension
     tube. (Theoretically there

@

www.butkus.us

Example:
   An exposure factor of 2
   means that the aperture
   or shutter speed has to
  be increased by one
    step.
(F8 -+F5.6 or 1/60-+1/30)
When the AE Finder-E  is     mx4used, however. automatic       Eo
exposure operations are      cr
possible without concernfor the exposure factor        1.,o a
because of the through-the-   3lens metering that takes        '.u
place.                                                                                                   I
                         oN3
                                              Jet,                          OoOg€
                                                            qo
                                    Exposure lncrease




                                @

www.butkus.us

Automatic Bellows Attachment-E





                               @