Housings:
Four independent housings
will be constructed to house the critical components of the hi res
system. The housings will be made of hi grade aluminum (6061) capable of
withstanding 3000psi. This will allow a range extension down to a max
depth of 6000ft if desired in the future without any major reworking.
Main Housing:
A cylindrical design is
well suited for this purpose as the round surface is the best shape
to withstand the extreme pressures and the flat ends are the
simplest way to mount the removable end cap and dome port. The
camera itself will be mounted on a flat shelf inside the housing
such that the lens lines up perfectly with the dome port without any
noticeable chromatic aberration.
Strobe Housings:
The twin Nikon Strobes are
to be mounted in separate aluminum cylinders with domed acrylic end
caps. The convex shape of the acrylic should help to widen the
strobes' angle of coverage.
Initially the system will
be tested to determine whether wireless communication will work
through the ports to fire the strobes remotely. If wireless
communication proves to be unreliable, Seacon bulkheads can
be installed to hardwire the strobes directly to the still camera.
Low Resolution Camera Housing:
The monitoring camera (a
tiny fisheye lens attached to a surface monitor) will be mounted in
a separate cylindrical housing attached to the top of the main
housing at an angle such that the topside photographer sees what the
housed Nikon Camera sees but with a broader peripheral view so that
images can be composed before the subject enters the field of view
of the Nikon camera.
Sled:
The sled will consist of an
aluminum frame upon which the main housing and strobe
housings can be secured. Forward of the main housing will be a bait
station where appropriate bait can be attached to lure in the subject to
be photographed. A bar will extend upwards and forwards from the rear of
the housing so that a tether can be attached at a point which will keep
the sled horizontal while being deployed.
Tether
and Umbilical:
A simple tether made of braided
steel cable is to be connected to the sled by means of a shackle. An
umbilical cable that controls the shutter release and transfers the
image from the monitoring camera to the topside station will be secured
at 10ft intervals to the braided cable. It is possible that the
stainless cable may not be necessary if it is determined that there is a
strong enough data cable available, i.e. one that is capable of supporting its own weight
and that of the sled's as it descends.
Winch
System:
Depending on the cumulative
weight of the housings, sled and cable, the winch may require a
motorized control or it may be able to be operated by hand. As the spool
will contain the data cable as well as the braided cable, a special
connector must be installed that can transfer the information from the
rotating spool to the static line to the laptop.
Surface Control Station:
In keeping with the simple
nature of the project the surface station does not need to be
particularly sophisticated. The only necessary controls are the remote
trigger mechanism and the station's monitoring capability. As well as
these, the ability to record the activity witnessed by the low res video camera
would be beneficial.
Consequently the information will be channeled to a laptop capable of
both tasks.
DSLR
Camera:
Although the ability to
remotely control all settings on the submerged Nikon camera would be
convenient it is not essential. The camera and strobes can be preset to
make sure that the bait station is always perfectly in focus and
appropriately lit. The camera settings will be pre-adjusted to facilitate
the greatest depth of field so that the subject will remain in focus
even when closer or further away than the optimum focal point.
Low Resolution
Monitoring Camera:
The monitoring camera must be
sensitive enough to pick up activity at the bait station in very low
light so that it is not necessary to attach a bright external light that
will discourage sharks and other deep water predators from approaching.
Although able to register an image in almost total darkness, the
monitoring camera's sensor plate must be robust enough to withstand the
brightness of the flashes emitted from the strobes when the Nikon camera
takes a picture.
Costs
of components and lead time associated with the project:
Prices are based on cost of raw
materials and labor.
Machining of
6061 grade aluminum housings (inc retainer rings) |
$2000 |
Machining of
custom acrylic dome port |
$1000 |
Acrylic flat
ports x 3 |
$300 |
Impulse
bulkhead connectors x 7 |
$1050 |
Strobe arms |
$300 |
Nikon SB800
strobe units x 2 |
$800 |
Booster modem |
$200 |
Laptop surface
station |
$500 |
Night vision camera |
$200 |
2000ft braided
steel cable |
$200 |
2000ft data
cable |
$500 |
Aluminum sled |
$300 |
Cable Master |
$200 |
Unless sponsorship can be
arranged, it is estimated that
construction will take approximately one year to complete.
If you have any questions
about Elasmodiver please e-mail elasmodiver@gmail.com
Elasmodiver Sponsorship opportunities are now available. If you would like
further information please follow this link:
Sponsor the quest to photograph the
world's most elusive sharks |