Port extensions can serve two purposes in underwater photography, one is purely physical in nature, it simply extends the length of a port to accommodate a longer lens or one equipped with accessories such as tele converter, as it is frequently the case with macro photographic configuration. The other has a direct influence on the optical performance of a lens, the extension ring being used, in this instance, for positioning a dome port as closely possible to a wide angle lens optical center. The wider the lens, the more critical this positioning will becomes, especially true of rectilinear type wide angle lenses covering field of views upward of 90 degrees.
The Aquatica Port Extension Ring (2.9 In.) is made of high grade 6061 T6 aluminum alloy, anodized to military specs and pressure tested to a depth in excess of 300ft / 90m. A sturdy, trouble free stainless steel locking mechanism insure that your port is reliably locked to the extension ring, the latter being safely held in place by the housing own locking mechanism. Aquatica has gone to great extent to provide you with the best tools for your photographic needs, providing you with no less than thirteen port extension rings, including four with manual focusing knobs on them, ranging in size from 16.5mm /.65" to a full 97.5mm / 3.82". This, along with the broad selection of ports at your disposition, makes Aquatica one of the, if not the most, comprehensive and accurate underwater photography system existing at the present.
Features:
Enables Use of Longer Lens and Teleconverter
Made of high grade aluminum alloy
Pressure tested to a depth in excess of 300ft / 90m