Nikon D90 User Manual page 18

When the standard viewfinder is installed the red and green LED's on the
hot shoe are visible right above the viewfinder, through the back window of
the housing. In case a 45° viewfinder or a straight viewfinder is installed, the
red and green LED's on the hot shoe are visible through the gap right above
the viewfinder.
- As soon as the HugyCheck system detects a pressure between
950 and 850 hPa, the red LED will blink once each second.
- When the HugyCheck system detects a pressure between 850 and
750 hPa, the red LED will blink 3 times each second.
- When a pressure of 750 hPa (or less) is registered the red LED will
stop blinking and the green LED will take over.
In case the housing hasn't been closed properly or in case an O-ring should
be faulty, the pressure of 750 hPa will not be reached or will not be kept. In
this case a loss of under pressure will be registered by the system and the
red LED will be reactivated while the green LED will stop blinking.
We strongly recommend to start the vacuum procedure at least
When opening the housing after a dive, the under pressure first has to be
released by unscrewing the one way valve from the bulkhead.
Hugyfot Housing for
Install the one-way valve into the 3rd bulkhead
and remove the sealing cap. Insert the plug on the
electrical vacuum pump into the one-way valve and
press the button on the pump.
With the stan-
dard viewfinder
installed, the
LED's on the
hotshoe are
visible through
the back
window.
30 minutes prior to the dive.
Nikon D90
With the 45° or
straight view-
finder installed,
the LED's on the
hotshoe are vis-
ible through the
gap above the
viewfinder.
18 User manual