Nikonos Photo User manual

NIKONOS
                                   r    PHOTOGRAPHY  the
    CAMERA ONd SYSTEM
          By Fred M. Roberts





iI                      o The Syslem
                      o Flqsh
                      o Close - Up
                      o Trouble Shooting

NIKONOS
                            r PHOTOGRAPHY  the
  CA'NER,AONd SYSTEfiI

    by Fred M. Roberts                                                            l
                                                                                                                                                            lj,
                                . CONTENTS
    l. INTRODUCTIONto theNlK0N0S35mmCAMERA.          lI
   2. SYSTEMACCESSORIESondLENSES.
   3. TheNlK0N0SABOVEWATER.
  4. TheNIK0NOSUNDERWATER.
  5. FLASHwiththeNIKONOS.
  6. CLOSE-UPPHOTOGRAPHYwiththeNIKONOS.
  7. APPENDIX.





          C O P Y R I G H T1 9 7 1 ,F R E D M . R O B E R T S
Allrights   reserved, including the right of reproduction in any torm in
whole or in part, under the lnternational, pan-American and IJniversal
conventions. Published in the united stafes by tmRoBERrs  Enter-
prises, P.O. Box 608, Dana Point, California 92629.


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FIGURE





FIGURE 1-3. BOTTOM VIEW OF THE NIKONOSCA MERA, ThE CAMETA
i s shown with the combination tripod socke t thread and  f lash connector
port plug removed. The white dof vis ible near the porf is the location for
the key of the f lash connector (refer to FIGURE 3-1). The /ens is shown
with  its key engaged indicating proper location of the /ens to f ilm plane.
The /ens may be mounted wi th either the tocus sca/e on the top (facing
the camera) or the aperture sca/e. However, the designers intended the
focus sca/e to be on the top, putting the focus knob on the left side of
the camera (camera facing subiect) and the aperture on the righf s ide.  lt
 i s important to be consi sfen t or you may move the wrong contro I in a
hurried moment. The body flash port plug should be operated with the
edge of a coin to avoid damage to fhe soft metal plug slot.


                            (A)





  FIGURE 1-4



FIGURE 1-4. SfANDARD N/KONOS LENSES. (A) The underwater 28mm
t/3.5  /ens; (B) The universal (above or below the water) 35mm t12.5
/ens and (C) The universal 80mm t/4  /ens. The underwater 15mm f /2.8
/ens and   i ts  specia I optical viewtinder are shown on page A-7 of the
Appendix. Las t minute intormation on the 1Smrn /ens was lim ited , there-
fore, it was added at the end of the text.
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INTRODUCTIONTO THE NIKONOS35mrnCAMERA

   The Nikonos camera is an integrated environment proof assembly of
waterproofbody and shutter with special sealed system lens. The ease of
use and portability of the 35mm camera are retained by the Nikonos, plus
the advantageof a self-containedsubmarinecamera without external case.

   The camera is designed to withstand water depths to 160 feet, offers
full use of all controls and settings while submergedand is synchronized
for either focal plane flash bulbs (FP) or electronic flash (1/60th second
or slower).

   The Nikonos is a viewf inder type camera not a SLR (single lens ref lex).
and depends on an external open frame sportfinder or an optical built-in
finder for the 35mm !ens. A 35mm wide angle lens is standardequipment.
   Shutter speeds are easily set at anytime, above or below water, and                         nuB'0,these speeds range from       bulb setting, 1./30th, 1,/60th, 1/121th,
1/259th, and 1/5O0th second. The same shutter speed control also carries
an "R"  or f ilm rewind position, Figure 1-13, which frees the f ilm take-up
spool sothat the retractablerewind lever can return the f ilm to the cassette.
PREPARINGTHE CAMERAFOR FILM LOAD OR UNLOAD
  Refer to Figures 1-1 and 1-2. The Nikonos is unlike a'normal 35mm
camera when film  is to be loaded. A standard camera generally requrres
only a back or bottom panel removal to expose the cassette cavity and
the wind spool. The Nikonos requires a lens removal first, then a body
separation.
REMOVALOF THE LENS
   The  first  order of business when the camera is to be loaded or un-
loadedwith film, is to removethe lens. This can be done easily by pull-
ing the whole lens outward, away from the body, until the two small pins
visible at the rear of the lens mount clear the notch visible at the top
and bottom of the outer camera body shell. Refer to Figure 1-5.

 FIGURE 1-5            FIGURE





   Turn the whole lens in a clockwise direction until the aperture and
focus control knobs of the lens are vertical instead of horizontal, Figure
 7-6. Now pull the lens clear of the body in an even gentle way to prevent
damageto the "O"  ring body seal
                                 1-3

SEPARATIONOF THE INNER & OUTER CAMERA BODY
   Set as ide the lens, carefu I ly, and examine the camera body assembly.
 Refer to Figures 1-1 and 1-2. Lift the cam on each side of the body and
 pf ace the projecting levers under the inner body lr.rgs, F igure 1-7, Apply
downward force to each cam at the same time to  lift the inner body clear
 of the outer body, exposing the main body seal "O"   ring. Pu| | the cam
arms out of engagementand out of your way, they carefully  lift the inner
body cfear of the outer case, F igure 1-8.





                                    ( B )                                                      ( A )

 FIGURE 1-7. BODy SEPARATION. Remove the /ens. (A) Place separa-
 tion cam under inner body lugs.(B)  Swing both cams toward the outer
 case to lift the inner case free of the outer case.




CASSETTE                                       TAKE- UP
                                          SPOOL
 FIGURE 1-8


PRESSUREIP LATE                                          INNER BODY





OUTER BODY

 FIGURE 1.8. /NNER AND OUTER CASE DES/GN OF THE N/KONOS.
 View shows the f ilm casseffe in place, with the film threaded under the
pressure plate and into the take-up spool. When returning the inner case
 into the outer, avoid catch ing the pressure plate springs on the edge.
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INSPECTION
  Examine the two "O"  ring seals now exposed during d isassembly,the..O"      ring seal ing the lens to tne ourer Dooy and the body seal between the
inner and outer body. These should be lubricated periodically with the
grease providedwith the camera, petroleumjelly, barium 0'O" ring grease
or as a very last resort silicon grease. Silicon grease is very hard to re-
move f rom areas where grease is undesirable, suc h as the g lass port of
the lens or the rear lens e lement. Wipe-off excess grease as  it may be
accidentallycarried where it does not belong by your f ingers. tt is best to
lubricate your seals at the time the parts are put back together, but do be
sure you c lean the seals and keep them c lean wh ile the camera is apart.
LOADINIGTH E F ILM
  Open your  f i lm box and re move the cassette  f rom its protective cover
or metal can. Place the cassette into the inner body as shown in F igure
 |-9,tolding the hinged cassette guide out of the way while inserting the
cassette rewind spool into the rewind fork.

   FIGURE 1-9
                                       PRESSURE
          LEADER                                                 P LATE

CASSETTE
                                                        F I L M
                                              SLOT


H I N GE DCA S S E TTEGUIDE

Carefully allow the hingedcassette guide to encircle the projectingspool
while keepingthe film leaderfrom betweenthe cassette and the inner body.
The hinged pressureplate on the Nikonos ll should be open while loading
f i l m .
   Dress the f ilm leader across the rectangularf ilm mask at the rear of the
inner body and insert the end of the leader into the slot in the cameratake-
up spool. Push the leader in as tar as  it will go, short of the end making a
full loop in the spool and exiting the same slot. Stop with one f ilm sprocket
hole engaged w ith t he s ingle project ing tooth of the take-up spoo| .
                                Carefu I ly ho ld  t he cassette in proper              FI G URE 1-10
                            posit ion , F igure  l- l0 and set the shutter
                                   re lease lever loc k on o'safe" , the pos-
                                                        it ion that would keep the shutter coc k and
                                  re lease lever in place when coc ked. Move
                                the shutter re lease-cock ing lever s low ty
                                   to wind-up the excess leader. When the
                              leader is well engagedand the f ilm comes
                              d irectly  f rom the cassette, stop moving
                                the   lever.

                                  1-5

Check the pressure plate surface  f or d irt, scratches or nicks.  lf you
 must remove material, use the skin of your f inger or thumb tip as the ab-
 ras ive and smooth or c lean in the same d irect ion as the  f i lm travels. Be
 sure your thumb or finger is clean - no saft water or dirt should be present.
        lf you use a cloth be sure it is soft and dirt free, and that you still move
  in the same direction as the f ilm travels so that scratches are smoothedin
 the direction they will  least damagethe film. Close the pressureplate
 after also removingany dirt that has collected on the film leader under the
   f ilm leader under the pressure plate and near the exit of the cassette.
   Remove dust and d irt from the body seal and lubricate if dry. Inspect
 the recess in the top of the outer body where the "O"  ring will seal. Run
 your f inger over the area to be sure it is smooth and free of dirt. place the
 inner body in the outer body, be sure the pressure plate springs do not
 catch on the outer body, and gently push the two units together.
   The f ilm counter autornaticallystarts from zero as the pin at the bottom
 of the outer case projects into the hofe at the bottom of the inner case near
 the counter. lf you plan to use flash  it  is a good idea to check the ffash
 terminafs projecting f rom the side of the inner case , F igure l-l  l, and the
 spring contact for the  f lash connector, in the outer case , F igure l-12, be-
 fore assembling the inner and outer body parts.
 F LASH CONTACT
                COUNTER            F I G U R E 1 - 1 1COMMON
BU L B
 SYNC.



    X SYNC.
           COUNTER RELEASE
 F IGURE 1-12
                                                                                      I N N E R B O D Y
                                         GUIDES





              COUNTER I N N ER                              COUNTER
              WINDOWCONTACTFINGERS               A C T I V A T I O NP I N
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Use a cotton tipped stick with clean alcohol to clean both the contact
f ingers and studs, then dry both with a new dry cotton tipped stick. Be sure
no material is left on either the f ingers or the stud after cleaning.
   With the inner body and outer body united install the lens you plan to
                 '0O"                         ring seal on the rear of the lens, clean and lub-use. Examine the
ricate sparingly. lnsert the lens in the reverse of removal, iris and  f ocus
knobs vertical to the body axis, focus knob near the top of the camera body.
Push the lens into the body gently, be sure the "O"  ring seal in the outer
body is also clean and free of dirt. Then rotate the lens clockwise until the
two pins drop into the body notches, Figure 1-5.
  The camera is now almost ready to use. Since a portion of the f ilm leader
has been exposed to light during loading it is neccessaryto clear this  f ilm
from the film mask to avoid partially exposed pictures at the beginning of
the roll. With the camera upright, looking down at the shutter cocking-
release lever, move the "safety"  lock into "safe"  position, then work the
lever several  t imes to advance the  f i lm w ithout cock ing the shutter or
causing the f ilm counter to register the movementof  f ilm.
   Unlock the "safety"  lever and leave the shutter cocking-release lever
projecting from the body. The shutter is not cocked, but the next stroke of
the lever will both cock the shutter and advance the  f ilm to the  f irst ex-
posure. lt  is preferable  f or long shutter I if e to leave the shutter uncocked
while not in use. Do not forget the lever "safety" lock - this little device
can cost film  if you try to cock the shutter with  it tilted toward the speed
knob. The shutter will not cock in this case nor will the counter advance,
but the f ilm still moves to the take-up spool regardless. Black unexposed
f ra me swillre su lt in color f ilm, clear frames if you us e B & W f i l m .
  When you are ready to use the camera f irst chec k the posit ion of the
"saf ety"  loc k , move it away f rom the lever, then in one motion pu| | the
cocking-releaselever over as far as  it will go.  lf you do not go the whole
way in one motion, but stop short of the cocking position, and release the
lever, the lever will swing back to the relaxed position and film will be
wasted. lf the shutter is cocked, the lever willstay  parallel with the body.
     lf you are not going to take pictures at that time, but wish to avoid ac-
c idental re lease of the shutter, now move the "safety" lever in behind the
the re lease lever. The shutter is safe from acc idental re lease. lt  is also
safe from use! Do rememberto move the "safety"  from behind the release
lever before attempting that Once in a lifetime photo. Refer to Figure 1-13.

              SAFETY
    FIGURE                                        SPEED
                                                                                                            I N D E X P O I N T



                                     SHUTTER
                                    SPEEDKNOB

CONTROL OPERATIONS
  The focal plane shutter and cocking and release lever are a novel comb-
ination control that can be easily operatedwith one finger of the right
handwhile grippingthe camerabody with the same hand.
  Speed settings are engraved and color coded for ease of use.All num-
bers except 60 are in black, while the number 60 and the letter "R"  are
 in red. Underwater,below 30 feet, all of the red numbers and letters will
appearblack so do not be confused. The camera is flash synchronizedfor
focal plane type f lash bulbs at any speed 1/3}lh to 1,2500thsecond, but is
only synchronized for zero delay electronic flash at 1/3}th and 1,/60th
seconds, the latter marked in red. In order to use zero delay electronic
flash the shutter curtain must be in the full open position while the flash
occures.Any other position will obscure part of the f ilm and only a partial
picturewill result. lf you should leave the shutter speed knob set at "R",
also red colored, and use strobe, the result will be partially exposed
 f rames.
   A white dot is located on the cock-releaselever that serves as a posit-
 ion indicator for the speed setting knob. The lever and the speed setting
knob move as one unit when the release lever is moved alone. However,
the speed setting knob can be moved as desired without disturbing the
lever.
   The "B"  setting of the shutter is a standard"bulb" setting which will
 allow time exposure as long as the lever is held released. When pressure
 on the release lever is relaxed the shutter will close. The setting should
 ngt be COnfUSedWith a "T"  O f "time"  Setting, not On this Camera,aS in
 that case the shutter stays open until the release lever is moved or re-
 leaseda second time.
   Figure 7-73, shows the cocking-release lever in the normal uncocked
 position.This is the best way to store your cameraand the position least
 likely to be released accidentally.
   When a new roll of film  is placed in the inner body, Shown in Figure
 1-8, the cocking-release lever is operated several times with the thumb
 safety in the "safe"  position (tilted toward the speed knob.) This ad-
 vancesthe film without cocking the shutter.
   Sooneror later you will probably repeat a shutter cocking step with the
 safety in place when you really wanted to cock the shutter.This results in
 unexposedfilm and the counter does not reflect the movement of film.
 Watchthe position of the thumb safety lock.
                                                          F I G U R E I - I 4
                                       SHUTTER UNCOCKED





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ACCESSORYSHOE
   The accessory shoe is designed to accept standard land photography
flash accessories and meters, while underwateror above, or  it will accept
special open frame sportfinders. Since the 35mm lens is standardequipment
for the camera the optical finder is designed to cover the field of view of
this  lens. A 28mm wide angle underwater lens and an BOmmabove or
below water telephoto lens are also available, but neither will  fit the
built in optical viewfinder. Each of the accessory lenses have a specific
open frame sportfinder, which  is  inserted in the accessory shoe. More
detailed informationon allof the Nikonos lenses later.
T O R E W I N DT H E F I L M
   The rewind lever operated much like  its topside counterpartexcept
that the unit must be pulled upward to engage gears within the camera
 body. To rewind set the speed selector knob at "R",  pull up the rewind
lever and wind in the direction of the smallarrow visible when the lever is
extended (clockwise). The rewind lever can easily be repositionedwhen
the inner body is removedfrom the case by holding the fork which engages
the film cassette spool with the left hand and gently rotating and pushing
inward the rewind lever with the right hand. Rotate the lever backwards
 (cou.nter-clockwise)if   it  will  not  insert readily. When fully retracted,
fold the lever over and place  it  in its recess in the upper portion of the
body. See Figures 1-2 and 1-13.
USE OF THE OPTICAL AI.ID SPORT VIEWFINDERS
  When the camera is loaded and cocked all that remains is to set the
shutterspeed,the properiris setting for the f ilm you are using, focus, aim
compose and shoot. Use of a  light meter is recommendedfor available
light photography.
  The aim for the camera can be obtained two ways. With the optical
finder for the 35mm lens or with an open frame sportfinder attached to the
accessoryshoe. Two open frame sportfindersare available, one for the 35
and BOmmlenses, and a second for the 28mm wide angle underwaterlens,
see Figure 1-15. Please note that the 28mm lens is designed to be used
only underwater.Above water the results will show curvature and distor-
tion to some subjects. Refer to the section on Nikonos lenses for more
d e t a i l s .

                   F I G U R E 1 . 1 5





       COMBINATION35 & 80mmSPORTFINDER

                                  1-9




                 ,L!f7ir:,

The optical viewfinder is best to use when the camera is above water.
         With some practice it can also be used while submerged.lt  is reasonably
         accurate over the range of the 35mm lens focus distance settings.
           Looking into the optical finder you will see a bright rectangularcon-
         tinuous border and three bright bars, Figure I-16. The main border rep-
         resents the true-size of the field of the 35mm wide angle lens. However,
         --since the optical finder is not exactly on the optical axis, but rather above
        and to the left of the lens, parallax is particularly noticeable for close
          pictures. Parallax is the name given to the difference between what the
          viewf inder "sees" and what the lens actually "sees".





                                                                                                                                          I
                                                                                                                                         I
                                                                                        l-  rrer-o                                                                      stzE               F.

                                                                                                                          \.    PARALLAx
                                                            CORRECTION.
                                                                     LINES


                                                                      FIGURE I.I6



        FIGURE 1-16. Camera body optical viewfinder. Field  of view with the
       35mm standard /ens ls outlined by a white  full rectangle, shown in black
            in the illustration. Parallax correction lines are short white bars set with-
             in the tield rectangle just below the top edge and to the right of the left
        edge of the field. To use fhese lines tirst determine the tield size of the
           picture, compose, than shift the field so fhat the parallax bars form the
             left and top lines of the original tield of view - take the picture.

            Refer Io Figure 1-17, consideringthe horizontal optical plane only, the
         viewfinder "sees"  the subject, but the lens is actually displaced to the
           right about 3.Scm(Centimeters).
            For moderate to distant subjects the parallax will probably not be too
         noticeable due to the small error, but for close subjeets  it may be very
         obvious. The small short lines in the viewfinder are parallax lines. Once
         you have framed your subject with the  border',move the finder so that the
          subject is framed in the same way by the short correction lines, Figure
          7-76. The camera is now displaced as in Figure l-17 (b),so that the op-                 nosees"           tical axis        the subject where the optical finder saw the subject in
         F igure 1-17 (a).

           Not only is the optical axis different in the horizontalplane, but also in
          the vertical one as well. The viewf inder is about 4cm  above the optical
          axis so the camera must be tilted upwardto compensatefor parallax. There-
               'j        fore, the correctionlines are low and to the right in the optical viewf inder- it      to compensatefor parallax you move the camera optical axis upward and
           to the left.
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                                                              .,":-r.'.:-i-:..---uiif

sEcTtoN2
SYSTEM ACCESSORIES
   The Nikonos is a system camera with threelensesanda close-up outf it
availableand, althoughnot standardwith the Nikon portionof the line, other
firms make Macro and Diopter type close-up lens devices and extension
tubes for the system.
STANDARDNIKONOSACCESSORIES
    1. UnderwaterB/C  f lash unit.
    2. Open-framesportf inders for the 35, 28 and 80mm lenses.
    3. Underwater light meter - case and Sekonic L-86 meter.
    4. Leather carrying case (above water use).
    5. Lens hood and f ilter holder for screw-in 52mmf ilters.
    6. Ultra-close-upattachmentusing a supplementallens, with a field size
     frames and mount for the Nikonos B,/C f lash unit.
    7. 21mmspecial underwaterwide angle lens.
    8. 80mm telephoto lens for both surface and underwater use.
    9. Flash adapter to bring internal sync connectorsout to a standard PC
      terminal tor PC type sync cords.
   lO.Special optical viewfinder for the 80mm lens (above water use).
   11. Adaptor hood and a line of 52mm screw-in f ilters.
NON-STANDARDNIKONOSACCESSORIES
   Non-standardNikonos accessories are those made by other than Nikon,
but designed to  fit the Nikonos camera. This  list grows all of the time so
the items listed below are only representativeof what probably exists at
t h i s t i m e .
    1. Close-up attachmentsfor the exterior of the standard lens.
    2. Extension tubes tor Yzi1,1:1 and 2:1 magnification.
   3. Flashcubef lash bulb guns.
   4. E lectronic  f tash units.
   5. Fish-eye Nikkor lens adapter for the Nikonos.
    6. Accessory shoe attached underwater light meters.
   7. Accessory shoe attached f lash units.
   8. Accessory shoe attached optical  f inder for f ish-eye adapted lens.
   9. Carrying cases for the Nikonos system.
  10.Lens focuser for establishing prime focus point for close-up work.
  The selection of accessories for your Nikonos will depend on what you
plan to  photograph and whether you use available light or require flash.
   Protective carrying cases are a very good investment to guard your
camerafrom scrapes and possible serious damagewhile not in actual use.
A sportfinder is helpful if you cannot get near the optical f inder, such as a
diver with a face mask. The flash adapter allows use of the Nikonos with
accessory shoe mounted f lash attachments, non-Nikonosbulb  f lash units
and electronic flash guns. The Nikonos has what is called a "cold" shoe.
A'ohot"  shoe is one that makes electrical connection to the inserted ac-
cessory while the "cold"  shoe serves only as a holder of the accessory.
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T he lens hood is a va I uable asset to reduce sun g lare and to reduce
surface ref lect ions on the lens or  f ilter in use. The hood is also des igned
to leak water betweenthe Nikonos lens and the filter for underwateruse so
that the hydrostatic pressure between the e lements is equalized to prevent
damageto the camera lens or the accessorydevice.
   Most of the other Nikonos accessories are for spec ialized use to  f urther
increaseyour versati I ity and improvethe overaI I system concept.
THE 35mmWIDEANGLE LENS
   The standard lens supplied w ith the N ikonos camera is the 35mm wide
angfe  lens. Th is I/2.5 lens, f ocusable  f rom 0.8 meters (2.75 feet) to in-
f inity, is an exce I lent compromise f or the d iver who wants both a camera
f or the surface as well as one he can take with him into the depths. The
 rangeof iris control if from t/2.5 to t/22, while the focus is calibratedin
 both the metric and English systems of measure, meters and feet.

   The optical quality of the lens is excellent, producingcrisp sharp re-
 sults both above and below the surface. Above water the lens is a wide
angle un it , be low water  it approaches what a standard 50mm normaI lens
for a 35mmcamera would do above water. The difference, of course, is due
to  t he index of refract ion of the water-glass-air interface between the sub-
ject and the f ilm. Refer to Figure 2-2 tor lens controls.

   The accessory sportfinder for the
35mm N i konos lens  is bu i lt  as a
duaI purpose unit  f or both the 35 &
80mm lenses, wh ich are both use-
ab le  above and be low the water.
Horizontal oarallax is almost elim-
inated w it h t he s portf inder as the ac-
cessory shoe is displacedonly 1.Scm
to the optical axis. Vertical parallax,
on the other hand, is even more pro-
nouncedclose-up as the finder axis
 is now almost 8cm above the optical
ax is. A central double ring is used
to  al ign the combinat ion 35-80mm
sportfinder, but th is does not correct
for parallax very we | | on the 80mm                             FIGURE 2-1. Nikonos 35mm Wide
lens. Experience is your best gu ide   Angle standard lens. Des igned tor
on where to aim the camera for the   photos above and below the water.
type of pictures you frequentlytake.
   Refer to F igure 1-l 5 tor a drawing   of the combination 35-80mmopen
frame sportfinder and the 28mm lens open frame sportfinder. Figure 2-8 il-
lustrates how the f inders should be used to avoid even more parallax due to
improperuse. Proper use of the open frame sportfinderwill mean all of the
dif ference in the world to your success with the camera - so get familiar
with its idiosyncrasiesearly in your camerahandlingexperience.

                                    2-2

DEPTH OF FOCUS





        !-ENS CONTROLS & INDICATORS

      lf you use the sportfinder frequently, do not try to position your subject
so that it  f ills the whole f ield of view. Here parallax would be the most not-
iceable if you made a mistake in aim. This problem is more noticable with
the BOmmtelephoto lens than with the 35mm lens as the framer is much
more critical due to its narrow f ield and short depth of field. Refer to Fig-
ure 2-3, for a better idea of the problemof vertical parallax with the acces-
sory shoe open frame sportf inders.
   Normally the designer of open frame sportfinders has no way of knowing
how far away from your particular subject you are going to be, but the de-
signer of an underyater camera knows, or should know, that most of an
underwater photographerspictures will be close rather than far distant.
Nikon literature packed with the combination 35-B0mmsportfinder claims
that this unit is without parallax for the distance of 2 meters (about 7 ft.)
underwater.This has proven to be essentially true for the 35mm lens, but
has yielded problemsfor the 80mm lens. For more on the B0mmlens see that
sect i on.                                                                                                                                                                                                                                   i
   Acceptance angles for the Nikonos 28,35 and 80mm lenses, in air and
underwater are compared in Table 2-1
PICTUREANGLE FOR NIKONOSLENSES. TABLE 2.1
          D IAGONAL   V E R T I C A L   H O R I Z O N T A L  M E D I A
   28mm      76             45             60          A i r
               57           34             45          Water
  35mm      62           37            53         A i r
              46          27             39          Water
  B0mm    3o02o'          17o.20',            25o20',        A i r
            22             1 3               1 9         Water

   The correct viewing angle and distance are shown pictorially in Figure
2-10, for both the 35 & BOmmlenses using the combinedopen frame sport-
f inder. With a  little practice one can get used to moving the eye back and
forth until the edges of the outer rectangle appear thin and the hole in the
double circles merges.Nikon, in their instructionsheet for the sportfinder,
indicatesthat the unit was designedsuch that the viewer, you,,shouldbe
about B5mm (3.3 inches) from the finder for correct results. This  is just
about the right distance for the diver with a face mask over his eyes.
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The 35mm lens can be adjusted to take pictures closer than the 0.8
 meters (2.75 feet) shown on the focus scale.  ln fact, at least three ways
exist to accomplishthis feat. Refer to the section on close-up photography
for supplimentallens attachmentsand extension tubes. The former is used
before the lens, and is removableunderwater,the latter is used behind the
 lens and cannot be removed underwater. The supplementallens has very
 little effect on the relative speed of the film. There is no neccessaryex-
posure correction, while the extension tube has great effect on the film
speed and exposure must be corrected.
  The third method of extending your focus, is through the use of depth of
field. In the section of the lens showing focus distance are two red f ingers
that move with the  iris control, refer to Figure 2-2. These bracket the ef-
fective focus zone for the particular f,/setting of the lens without acces-
sories like the supplemental lens or tube in place. Every lens has one
critical focus point, where the focus is the best (the circle of confusion
the smallest), but on each side of this point is a zone that is considered
acceptable.The distance from the rearwarddistance to the forward is cal-
led the Depth ot Field.
   The depth of field varies with the t/number setting, the more wide open
the lens the narrower the depth of field. The more stopped-downthe lens
the wider the depth of f ield. Use your 35mm lens to illustratethe situation.
Set your iris at I/2.5, observe the position of the two red fingers on the
focus scale, note how close together they come. lf you had focused your
camera at 0.8 meters (2:75 teet) your depth of  f ield or the distance from
your lens to your subject must be very accurate.  lf you make an error,
the quality of your pictures are degraded and lose sharpness or are just
plain out of focus.

   Set your iris at f/22, leave the focus scale the same. Now the red in-
dicators are as wide as they can go. lf you took the same picture as before
you can now make a fairly large error in distance without seriously affect-
ing the quality of the results. ln fact you can move in closer than 0.8
meters, approximately 23cm or  9 inches to be specif ic,  in air, and get
acceptablesharpness.Underwaterthe apparentdistance would be the same
though the exact distance would be 3/aof the measureddistance.
  Now  if you have become reasonably good at guessing the apparent dis-
tance, rememberyour own eye focus is affected by the index of refraction
of the water-glass-airinterface of your face mask, you can use this depth
of  f ield to great advantage.
   For example, if your subject was thick, or like a fish at an angle to your
view, you would want the central point of the subject to fall on the line of
focus. See Flgure 2-4.
   The result of proper f,zstopcontrol is that both ends of the fish are in
focus. lf the subject was a ballor spongethe same situation would be true
 if you wanted the whole object to be in focus. However, suppose that a
small fish is in front of the round object in  Figure 2-4.      lf you are more
interestedin this subject than the whole large one, but you want them both
in focus, you must arrange your depth of f ield to  f it the situation, refer to   :

                          ?4

Judge the closer subject distance and the far subject distance; set your
apparent focus to a point half way between and your iris to an f,/number
that provides a depth of f ield that covers the near and far subject distances.
Doing this sounds complicated,however, it is a photographictool you have
 if you wish to use it. Rememberthat  if you set your f,/numberto correctly
cover your requireddepth of  f ield you will probably also need to change
your shutter speed to match the new f,/number at the ambient light level.
 lris opening and shutter speed are inversely related in uniform standard
steps so that you can use almost any camera and come out with the same
amountof light reachingthe f ilm plane.
   The f,/numberor f,/stop, if you prefer, is a function of the focal length
of the particular lens divided by the diameter of the iris opening. Larger
lenses are proportionallylarger, focal length and iris opening, smaller len-
ses are just physically smaller. lt is the simple ratio of the focal length &
the iris opening that controls the light striking the f ilm at a given speed.
   Standard f,/stop numbers, representing full whole stops are shown in
Table 2-2. The corresponding increase or decrease in shutter speed is
shown in comparison.The table is based on the assumptionthat the light
level was such that with a particular film an acceptableexposurecould be
made at t/2.5 with a shutter speed of 1,2500thsecond. The table is used as
an example, a guide to what happens between f,/numbersand shutter speed,
not what you should use without first conqulting your light meter..

 RELATIONSHIPf/STOP & SHUTTERSPEED - TABLE 2-2
          f /ST OP    2 . 8  4 . O  5 . 6           I     1 1    1 6    22   32
   SHUTTER     1     1     1      1     1     1      1     1
    SPEED     500   250   125    60    30    1 5     8      4



   Each number represents % or twice as much light as the adjacent f,/stop.
The same thing can be achieved by changing the shutter speed, again  if
you will observe your speed dial, each speed is lz or twice as much as the
as the adjacent numbers.Therefore, if you close your lens tromt/4tot/5.6
you reduce the amount of light reaching the film, to compensateyou must
decrease your shutter speed, allowing the light to  fall on the film for a
longer period of time. The lens opening lets in /z ?s much light from t/4to
f5.6, so you must increase the length of the exposure by decreasing the
shutter speed from say 1/500th second to 1,2250thsecond to make up the
difference. The result is identical exposure to the f ilm.
   Once you get used to the system of f,/numbers or stops, changing the
shutter speed can be almost automatic - change the lens iris two stops,
change the shutter speed two steps. The numbers representing the size of
the iris opening might be a little confusing at first - the larger the number
the smaller the opening and the smaller the numberthe larger the iris open-
 ing. This  is true because the f,/number represents a ratio of the frcal
length divided by the size of the iris opening. Since focal length does not
change,and the iris does, the numerical results of the ratio are inverse.
                                 2-6

Table *2,  is just an example of this relationship. The combinationof
shutter speed and lens f,/numberwill depend on the film you select. The
faster the film the smaller the lens opening for a given shutter speed.
Naturally where you want to maximize your depth of field, fast film  is
usually the best answer.Wherehigh quality is more desirable than depth of
f ield, slower speed f ilms are preferred.Further discussion of f ilm speed re-
lationships will be made in the section dealing with  f lash and ultra-close-
up photography.
   Before leaving the discussion on depth of field one other useful result
can be obtained by using the depth of f ield as a photographictool. At least
once you have probably photographeda person or object in front of a not too
pleasant background. lf from habit you used the largest f,/number,the smal-
lest  iris opening, and a speed sufficient to stop motion, then the back-
ground was also probably in focus with the main subject. Take a girl in
front of a chain link fence. The fence does not add much to the picture.
Use the opposite extreme, lens wide open, high shutter speed, to narrow
the depth of field. The girl will be in focus while the fence is diffused or
out of focus.
   This selective focusing can be used both above and below the water. lf
the subject is more importantthan the background,you can subdue the back-
ground by using larger lens openings (smaller f,/numbers).Rememberthat
you must be more accurate in your judgement of apparent subject distance
to the lens or your subject might be out of focus while the backgroundor
foreground is in focus.

 28mmWIDEANGLE UNDERWATERLENS

  A second wide angle lens is provided for in the Nikonos System. The
28mm lens is designed for the underwaterphotographerwhere dirty water, in
particular, makes it very diff icult to get back far enough to get the whole
subject. Naturally one cannot expect to get a full length view of a large
sunken vessel, unless the water is almost as clear as the air above the
water, but you would have a better chance with the 28mm lens than with the
35mm standard  unit.  Refer  to  Figure  2-6 for  the  lens configuration.
  The 28mm lens  is not intended for surface use, but  is corrected for
underwater aberrations and distortion. Used above water  it  will produce
f ield curvature called  barrel d istortion. F igure 2-7 shows a series of
actual photographs taken with the various lenses above and below the
water to show how the field size differs under the two conditions.
  The 28mm lens focuses from 0.7 rneters (2.25 feet) to  inf inity and is a
"slower"  lens than the 35mm unit in that the maximumf,/numberis t/3.5.
The iris range of the 28mm unit is from f,/3.5 toI/22.  Refer to the section
on depth of field under the 35mm lens for the principles of use as  it is the
same except for the width of  f ield - the 28mm lens is greater due to  its
shorter focal length. The shorter the focal length the wider angle the lens.
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The 28mm lens has its own acces-
 sory sportf inder and th is   f inder  is
 also  des igned  to  be  used wh i le
 underwater.  T he    f inder,  however,
 is made of rubber not plastic like the
 combinat,ionunit for the 35 & 80mm
 lenses. Un less you use care wh ile
 inserting the  f inder in the accessory
shoe, you can build-in a parallax prob-
 lem. Be sure the f inder is well seated
 ih the shoe and is not cocked to one
side or the other. Further it is quite
easy to lose the f inder if poorly f ixed.
   Like the sportf inder for the 35 and
80mm fenses, you must move your eye   FIG{JRE 2-6.   Nikonos 28mm
back and forth for a narrow edge pro-   Wide Angle  /ens. Dqs igne.Q.for
 f ife of the frame white reduc ing the    y?:,^.Y!!:rwater   only  without                                                   stort t on 'crossbars to  I i nes . Ref er to F ig ure ?B                                     ,
  The 28mm lens is a high quality optical unit producingsharp focus slides
or negatives over a wide range of distance to the subject. lt will allow the
photographerto get c loser to a g iven subject than the 35mm lens  f or the
sanF field of view, therefore, it performs better when water clarity  is con-
s istent ly poor. However, no lens , rto matter how we l I made, can "see"
through d irty water.
   The rubber sportfinder for the 28mm lens is designed for use underwater
and will see most of the field of this lens at distances of from 6 feet and
beyond,parallax is still to be consideredfor close work. The center of the
finder axis is about 8cm above the optical axis and about 1.Scmto the left.
When shooting subjects perhaps as close as 3 feet, parallax will begin to
take its toll in spoiled photos. To compensateafter framing move the sport-
f inder tield of view slightly to the left and tilt the camera upward to correct
for parallax. Moving the center of your picture about 2/3rds of the way down
the vertical bar of the finder will be just about right to correct vertical
parallax at d istances around 3 feet.

SOmmTELEPHOTO NIKONOSLENS

   The Nikonos 80mmtelephoto lens, like the 35mmwide angle lens, is de-
signed for use in either air or underwater.lt is a 4 group, 4 element design
front port excluded, with a  f ield angle of 30 degrees 20 minutes in air and
about 22" underwater.The lens will  of fer about a 2.03x  magnif ication
of the film image at about the same distance from the subject as with the
35mm lens. Refer to Figure 2-9.

   The f,/numberrange is from t/4  to t/22 and the focus from  I meter (3yo
feet) to infinity. The depth of field  is very narrow and the effective speed
of the lens the slowest of the three discussed.High speed film is definitely
recommendedun less you are ab le to determine the subject d istance very
€rccuratelyand can hold the camera very steady while shooting. lt  is more
                                  2-8

28mm /ens above water.          28mm /ens below water.





    35mm /ens above water.          35mm /ens below water.





    80mm /ens above water.            80rnm /ens below water,
FTGURE2-7. Comparison of field sizes of Nikonos 28,35 & 80mm /enses
from the same station. Nofe that the 28mm above water infinity picture is
not sharp. lJnderwater size comparison is based on fesf panel resu/fs,
photos are darkroom simulated with  the  f ish the key  subiect for size.





                (B)  CORRECT
FIGIJRE 2-8. Combination sportfinder for the 35 & 80mm /enses . Aim by
minimi zing edge width of the cross-bar and center circle as shown above.
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necessary than ever that you hold your camera steady or use high shutter
 speeds to avoid subject blur from camera movement.
   There is a place for a telephoto lens underwater. lt may seem to be the
 last thing you'need underwateras the 35mm camera standard 50mm lens
 (not the Nikonos) acts like a telephoto lens due to the index of refraction
 and this reducesthe effective f ield of view.
   Have you ever tried to photographa hermit crab going about his business
 on a submergedrock? He 1ust does not like a big photographerto get too
 close - result, you get a picture of the shell rather than the animal. How-
 ever, with the 80mm lens one can move back a respectabledistance and the
crab or fish will no longer worry about your proximity. Small reef fish are
 anotherprime candidate for the BOmmlens as they stay alive on the reef by
 staying away from large fish and for all practical purposes an underwater
 photographerlooks like a large fish. For best results with the 80mm lens
the water must be clear.
   The depth of field indicators on the lens are used in a manneralready
discussed and you can see upon examination that you cannot stand much
error in distance with the lens set at low f,/numbers.The depth of field for
example at t/4  is probably less than 5cm (2 inches) and  it  is nearly im-
 possible to estimate distance from the lens to the subject !his accurately
when you are 1.1 meters (3.5 feet) away. However, with an f,/numberof 22,
the depth of field opens to just under 30cm (12 inches) and this  is more
acceptable to estimating distance.
  How can the photographeruse the higher f,/numbers? Fast film and
slower shutter speeds. Unfortunately slower shutter speeds cause blur  if
the subject moves or you move the cameraduring exposure.This combination
 of problems is best solved with some form of artificial light source rather
than available light unless you use a tripod. Electronic f lash is a good
solution as these have a  light duration from 1,21000to 1,/10,000thof a
second and workvery well as a subject stopper if the available light level
 is not so high as to cause a double exposure. More on this subject later in
the section of this manualdealing with f lash.
      lf you chose to measure distance accurately underwater then the ap-
parent distance the camera lens "sees"  (the same one you see through
your mask), now becomesthe real distance and you must correct the focus
scale or your subject will be out of focus. For example, if the actual dist-
ance measuredto the subject from the lens was 4 meters,then,multiplyby 3/a
or 4 x 0.75= 3 meters. Set the lens focus scale on 3 meters rather than the
real 4 neters as the lens thinks the subject is at 3 meters due tothe index
of refraction of the glass in the lens.
 lf you are estimating distance from the subject to the lens, the apparent
distance, the lens sees the same thing and no adjustment is required for
refraction focus d istance.
  The correct use of the sportfinder for the 80mm lens is critical. Since
you are now working with a narrow f ield lens at a considerabledistance to
a subject, parallaxcan be quite a serious problem.Like the 35mm lens, the
sportfinder axis is about 8cm high and about 1.5cmto the left of the optical
axis. At one meter that represents a very serious aiming error, refer to
F igure 2-10.
                              2-10