AquaTech PD-16" Dome Port

The secret to the perfect Over/Under

PD-16" Dome Lens Port For a long time, the secret to capturing the perfect Over/Under image has been kept close to the chest of some of the worlds best water photographers. We’re pulling back the curtain and introducing the PD-16”, a limited release 16” Dome Port.

Over/Unders or “Split Shots” are some of the most sought after images when it comes to underwater photography. They combine the scene above the water level, with the view below the water's surface to create an image which is not possible to see with the naked eye. They’re an image that connects the terrestrial world with the marine environment from a perspective that can only be seen by the use of specialised equipment.

Why 16"?

There are in fact many reasons why you would use this specialised equipment, but there are 2 main reasons large dome ports are used for creating over/under images. Magnification and Dome Radius.

The curved surface of a dome port counteracts the magnification effect that happens to light when it passes through water. When viewed through a flat surface (like your snorkel mask or a fish tank) subjects underwater will appear bigger than they actually are. This is not a problem when your entire composition is underwater, but when you want to view a subject above and below the surface things begin to get weird.

The large radius of a 16” dome also adds more distance between the camera lens and the water surface. This distance allows the lens to easily see above and below the water plane and also provides a smaller water line in your image which is less distracting and more visually pleasing.

Lens Selection

It is possible to use a wide variety of lenses and focal lengths in combination with the PD-16" Dome Port. From fisheyes to 50s, it's just about possible to fit any wide-angle lens in the PD-16. When choosing a lens it is practical to use an extension port in the same fashion as you would when using an 8" dome port to achieve the best results. So if your lens is shown as requiring an extension to work with the PD-85 on our P Series Lens Port Chart, then the same combination would generally apply when using the PD-16".