When used underwater, flat ports bend light in such a way that the resulting image is magnified. This makes flat ports ideal for shooting small subjects with a standard, macro or zoom lens.
The Modular Glass Flat Front features a durable, optical grade glass front element. Lens Extensions are available in a variety of lengths to accommodate most popular portrait and macro lenses. The Modular Glass Flat Front does not attach directly to a housing. A compatible Lens Extension is required. Each Lens Extension simply threads into the base of the Modular Glass Flat Front. A strap wrench is included for easy removal.
Note that if a port is long enough to accommodate the full length of a 1:1 macro lens, the lens may vignette at infinity when used behind a flat port. A flat port reduces the angle of coverage of a lens when used underwater. If you're shooting a wide angle or super-wide angle lens, we recommend using the Modular 8-inch Dome instead to preserve the full angle of coverage of the lens.