18
Optional
strobe
attachment
balls
can
be
attached
to
the
strobe
mounting
bases
on
the
housing
or
onto
the
top
of
the
handles.
There
are
two
ways
of
connecting
strobes
to
the
NA
‐
D90
housing:
A)
by
optical
connection
through
the
Optical
Bulkheads;
B)
by
electrical
connection
through
the
Nikonos
5
‐
pins
bulkhead.
A)
Using
the
Optical
Bulkheads
The
built
‐
in
pop
‐
up
flash
of
the
D
‐
90
camera
can
be
used
as
a
commander
to
send
out
signals
(including
i
‐
TTL
commands)
to
the
strobes
via
the
2
Optical
Bulkheads.
It
can
be
utilised
in
different
ways
depending
on
the
type
of
strobes
connected
to
the
housing:
1)
Nikon
i
‐
TTL
compatible
strobes
such
as
SB
‐
R200,
SB
‐
600,
SB
‐
800,
SB
‐
900:
These
strobes
can
fully
utilise
the
Nikon
i
‐
TTL
controls
protocols
enabling
individual
TTL
exposure
compensation
of
each
of
the
2
strobes
connected
to
the
Optical
Bulkheads.
Do
ensure
that
the
other
ends
of
the
optical
fibres
are
pointing
onto
the
light
sensor
window
of
the
strobes.
To
set
the
D
‐
90
camera
to
i
‐
TTL
Commander
mode,
under
Menu,
scroll
to
Custom
Setting
Menu
(Pencil
shaped
icon
on
the
left
of
the
LCD
screen),
enter
‘e’
Bracketing/flash
.
