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The
Nikon RS underwater camera system
by
Brian Pitkin
Reproduced
from in focus 44 (Apr.
1992)
As
no doubt most members will be aware by now, Nikon have announced
a new 35 mm format single lens reflex (SLR) camera and flashgun
designed exclusively for underwater use. Despite the plethora
of articles which have already appeared in the diving press,
it was felt worthwhile including a feature on this important
and long awaited technical advance in our specialist field
in this issue of IN FOCUS.
At
the outset I should make it clear that the Nikonos RS is not
an upgrade of the Nikonos V, but a completely new and exciting
camera. Before you rush out to buy one however bear in mind
that it costs two ormore times as much.
THE
BODY
The
body is made of die-cast copper silumin oxidised aluminium
alloy and is about a half as large again as the Nikonos V.
A motor winder is integral. At 7.7 x 5.9 x 3.3 inches (196
x 151 x 85 mm) it weighs in at 72.7 ounces (2.06 gms) on the
surface and 32.4 ounces (920 gms) underwater. All joints are
sealed by "0" ring gaskets and the camera is able
to withstand pressures down to 100 metres.
The
body_is ergonomically designed so that it can be readily gripped
with the right hand, the shutter release button failing readily
under the thumb. There is a power manual focus lever just
where the right fore finger lies, making focusing simple and
easy. On top of the camera are the exposure compensation/ISO
film speed control, the shutter speed control and the exposurelmetering
control.
To
the right of the viewfinder and mounted on its flank in front
of the shutter speed control is the focusing control. On the
opposite side to the grip lie the flash synchronisation and
remote control terminals. The flash terminal accepts the new
Nikon SB-104 flashgun.
Flash
synchronises from 1/30th to 1/ 25th of a second in automatic
mode. In manual mode the shutter fires at the up to a maximum
of 1/25th. At manual speeds higher than 11125th the shutter
is automatically set to 1/25th. The flash ready light is incorporated
in the viewfinder.
The
viewfinder is offset at nine degrees and is an action type
with a large view. The highpoint is 60 mm which should allow
easy use underwater whilst wearing a face mask. The viewfinder
uses a BriteView screen for maximum sharpness and clarity.
A bright LCD readout provides comprehensive information on
the camera's settings.
Access
for loading film is via the hinged lockable back, reminiscent
of the Nikonos V, but there is an additional inner camera
door for access to the film compartment. Film speed is automatically
set by the DX code reader in the camera (speed of non-DX coded
film can be set manually) and this speed is displayed in the
viewfinder (along with the manually selected film speed) and
exposure compensation value. The battery chamber, rewind lever
and rear- curtain flash sync switch (see below) are safely
within the camera's back. The frame counter, illuminated by
an LCD, is of the additive type, and counts backwards as the
film is rewound (automatically when the lever is turned).
If this is anything like the rewind on my Pentax then this
means that in camera double exposures are possible.
THE
LENSES
Nikon
have produced three lenses for the Nikon RS:- a 50 mm, a 28
mrn and a zoom 20-35 mm.
The
Micro-Nikkor 50mm allows for close-ups down to 1:1 or life
size with an aperture range of f2.8 - f22 and a focusing range
of infinity to 0.55 ft (0.167m). It is 4.0 in diameter x 5.0
inches long (103 x 126mm) and weighs in at 38.8 ounces (1,10Ogms).
It has a picture angle of 35'.
The
28 mm lens is the standard lens with a focusing range of infinity
down to 0.85 ft (0.26m) allowing for close-ups down to 1:6.
It has an aperture range of f2.8 to f22, like the 50mm and
is 3.9 inches in diameter and 3.3 inches long (99 x 85 mm)
and weighs 19.4 ounces (550 gms). It has a picture angle of
59.8°.
The
zoom 20-35 mrn lens is the first underwater zoom. it has a
focusing range of infinity to 1.2 ft (0.38 m) and a aperture
range of f2.8 to f22. It is 6.4 inches in diameter and 5.1
inches long and weighs in at 61.7 ounces (1,750g). It has
a picture angle of 79° down to 51°.
FOCUSING
The
Nikonos RS has five different focusing settings. You can either
take pictures using single-servo autofocus, autofocus lock,
continuous-servo autofocus, freeze focus or power manual focus.
Single-servo
focus assures that the shutter is automatically released the
instant the subject is in focus. You can also compose your
picture with the subject off-centre by using the autofocus
lock.
Continuous-servo
autofocus automatically tracks a moving subject and predicts
its position at the precise moment you trigger the shutter.
Freeze
focus "waits" for the subject to move into focus
and when it does releases the shutter.
If
you want to control focusing then the power manual focus allows
you to do so. The viewfinder display indicates whether the
subject if in focus, focus- tracking or out of focus.
EXPOSURE
CONTROL
The
Nikonos RS uses five segment matrix metering, which it is
claimed makes short work of quickly changing and complex lighting
and can work in landscape or vertical mode.
If
you select aperture priority auto-exposure then you can set
the aperture to determine depth of field and the camera system
automatically sets the matching shutter speed for correct
exposure. The viewfinder display indicates whether aperture
priority or manual exposure has been selected. The matrix
metering is claimed to be so sophisticated that it can also
allow for automatic balanced fill-in flash!
If
you set the shutter speed manually then centre weighted metering
is automatically activated. This concentrates 75% of the metres
sensitivity - to the 12mm centre circle of the viewfinder
and allows for TTL control over the exposure.
There
is a "B" setting for long exposures and exposure
compensation by +P 2 EV in 113 step increments. The shutter
speed in use, deviation from correct exposure and exposure
compensation mark are displayed in the viewfinder.
THE
NIKONOS SB-104 FLASHGUN
The
Nikonos SB-104 has a guide number of 16 in metres (presumably
with 100 ISO film) and covers 100o, recycling in only 3 secs.
It is powered by a removable, rechargeable Ni-Cad battery
pack which is shielded from the flashgun main electrical chamber
in case the rear door seal is breached.
It
can be set for matrix balanced fill-in flash, centre weighted
TTL flash, manual flash (full; 1/4; 1/16 power settings) or
rear curtain flash sync. The later can be used to produce
the trailing image effect of a speeding object as the flash
fires as the shutter closes rather than as it opens, but the
camera must also be preset before closing the camera back
to use this facility.
The
flashgun can be used a a normal flash, as a slave flash, as
a flash slave in multi-flash operation or as signal flash
and has a test setting.
The
self diagnosis signals include a flash ready light, a heat
signal, a moisture signal and a flash performance signal.
CONCLUSIONS
Nikon
look as if they have done their homework on this one. The
Nikonos RS is big and at around £1000 for the body alone
its expensive. God and Ocean Optics Ltd only know how much
it'll cost to service and repair, but I can't wait to try
one. |
