9
THE INTERCHANGEABLE PORT SYSTEM
For your SUBAL housing, there is a wide range of front ports available, the largest of all
manufacturers. This allows you the use of a multitude of regular lenses under water, ranging from
fisheye lenses, extreme wide angle-lenses, zooming lenses and macro lenses.
The port O-ring
Please pay attention to all that is advised in chapter USE AND MAINTAINANCE OF O-RINGS!
Be sure that the O-ring and the sealing surface is clean and lightly lubricated.
Inserting of the frontport
SUBAL-frontports are attached to the housing by a bayonet mount.
Turn the port locking knob 180°.
Insert the port (after checking as described above) into the housings bayonet with the white dot or the
SUBAL-logo pointing towards the front main dial control knob.
While pushing in, turn the port 90 ° clockwise until it stops. If properly installed, the white dot or the
SUBAL-logo is aligned with the middle of the housing.
Now you can close the port locking knob.
Most important: After installing check thoroughly that the O-ring is seated correctly in its
groove and does not protrude from the housing.
To remove the port turn counter-clockwise until it stops and then turn back a little bit.
Do not change the port if it is very warm (eg. through irradiation from the sun, etc.)!
Synthetic material from which the ports are made expand more than the aluminium housing body and
may therefore jam in the mounting.
When travelling by aircraft the frontport should be left mounted to the housing ONLY if the port
O-ring and/or the body O-ring is removed.
Cleaning the front glass
The front glass of the ports are to be cleaned carefully to avoid scratches. If possible, rinse well in
freshwater, let it dip off and dry with a soft cloth carefully. Dried lime/salt spots are very hard to
remove!
Faint scratches are filled in by the water and stay invisible but with greater damage, it may be
necessary to replace the front glass.
The fogging of the front glasses can be avoided by inserting Silicagel or by applying an antifogging
liquid.
DOMEPORTS
Domeports are ports with a curved front glass. They are mainly used with wide angle lenses to keep
the same angle of coverage under water as on land.
When using domeports for wide angle lenses, please note the following:
Dome glasses act in water like lenses, creating an apparent image of the actual subject, which is
smaller and closer than in reality. The lens must be focused on this virtual image. The required
adjustment of the lens is in the region of 0.15 to 0.2 m. A dioptre lens on the camera lens restores
the full focusing range under water. The needed power of the dioptre lens depends on the lens type.
Without these correcting lenses you may not even be able to get your subject in focus!
