Using ND Filters and Polarizers with Outex: Four Configuration Options

There are four ways to use ND filters and polarizers with the Outex waterproof camera system. The right option depends on whether you need a fully waterproof solution, whether you're shooting above or below water, and the type of lens you're using.

ND filters help control depth of field and dynamic range in bright environments by allowing you to manage f-stop without overexposing the image. They are especially useful for cinematography, where shutter speed and aperture are often preset and cannot be freely adjusted during a shoot.

Option 1: Open Front — Above-Water / Water-Resistant Use

For above-water shooting in rain, mist, sand, mud, or dirt, you can leave the front of the Outex cover open and place your filter directly in front of the lens instead of attaching an Outex front glass port. The cover seals around the camera and lens body, providing water resistance from the sides and rear, while the filter sits at the front opening.

Best for: Rain, mist, beach, and surface shooting where full underwater waterproofing is not required.

Open-front configuration: filter placed at the front opening instead of the Outex front glass port.

Option 2: External Threaded Front Port — Fully Waterproof (Including Underwater)

Outex flat front glass ports have external threads on the front, allowing you to attach a filter or polarizer on the outside of the port for a fully waterproof solution — usable even underwater.

The thread sizes work as follows:

• Outex front ports below 77mm — external front thread size is 77mm. Use a standard 77mm filter.
• Outex front ports 77mm and above — external front thread size is 89mm (non-standard). Use the Outex 89–95mm adaptor (available from Parts) with a 95mm filter.

Best for: Underwater shooting where you need a filter attached to the outside of the housing.

Outex front glass port with external threads for attaching filters or polarizers. View product →

Option 3: Dome Port with Clamp — Filter on Lens Inside the Dome

If you want to use a filter or polarizer with a lens that doesn't have front threads (fisheye, hooded, or convex-front lenses), or if you simply prefer to keep the filter on the lens itself, you can use an Outex Dome port with a dome clamp. Here's how:

1. Attach your ND filter or polarizer to the lens filter thread as normal.
2. Use an Outex dome clamp (sized to match your lens diameter) to secure the dome around the lens and filter combination.
3. The dome encloses the lens and filter, providing full waterproofing while the filter remains on the lens inside.

This is the same process used for unthreaded lenses — the clamp anchors the dome to the lens body rather than the filter thread. Either dome size (120mm or 180mm) works for this configuration. Both dome kits include a clamp or adaptor.

Best for: Lenses with or without filter threads where you want the filter inside the dome, or for lenses where the filter thread is not accessible from outside the dome.

Lumix 10–25mm f/1.7 ASPH on a GH5 camera, using the Outex Dome 120mm with an 88mm dome clamp and ND filter on the lens inside the dome.

ND filter secured on the lens inside the Outex dome port.

Option 4: Internal Filter — Filter with Front Threads, Port Attached Outside

If your ND filter or polarizer has front threads (many screw-in filters do), you can attach the Outex front glass port directly to the front of the filter rather than to the lens. The filter sits between the lens and the Outex port, inside the housing.

Important: This only works if your filter has front threads that match the Outex port size. Not all filters have front threads — check your filter specifications before attempting this configuration. Also be careful not to over-tighten the port onto the filter threads.

Best for: Photographers who already have a filter on the lens and want to attach the Outex port without removing it.

Where to Find These Components

All of the above options — exposed-thread front ports, dome kits, dome clamps, and step-up ring adaptors — are available in the Parts and Accessories sections of the Outex store.

If you have questions about which configuration is right for your specific lens and filter combination, contact the Outex support team:

• Email: support@outex.com
• Phone: +1 (818) 583-7731

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