There are several options for using polarizers or neutral-density filters with the Outex waterproof camera system:
There are several ways to utilize an ND filter or polarizer with your camera lens when using the Outex waterproof system. This blog shows four (4) different options ranging from external, internal, and dome port use that secure filters to the lens of your choice. ND filters can help focus, sharpness, and dynamic range in bright environments by allowing the photographer to control depth of field and f-stop without over-exposing the image. It is specially useful for cinematography, when there are more stringent limitations on what the user can preset beforehand.
Option 1. Keep the cover "open" in front with your filter instead of the Outex front port for water-resistant/above water use (rain, mist, sand, mud, dirt, etc.).
Option 2. We make flat front glass ports that offer external threads so they can be used with filters or polarizers on the outside/front port for a waterproof solution (even underwater). Outex front glass sizes below 77mm have an external front thread size of 77mm. For Outex front glass sizes 77mm and higher, the front port thread size is 89mm, which is not an industry size. So we sell an 89-95mm adatptor/extension that you can use with 95mm polarizers or filters. They are both available in Shop By Parts.
Option 3. Purchase an Outex Dome port (both/either size would work), then use an Outex Dome clamp to fit/match the lens' diameter size. In other words, use the lens filter thread for the filter/polarizer, then enclose them within the dome, but using a dome clamp around the lens to secure it within the dome. This is the same process we offer for un-threaded lenses, such as fisheye, permanent hoods, or convex glass lenses. See image below with Lumix 10-25mm f/1.7 ASPH lens on a GH5 camera, using the Outex Dome 120mm with an 88mm dome clamp. Both/either Dome Kits include a clamp (or adaptor).
Option 4. Or you can use them inside the housing if the nd filter or polarizer itself has front threads onto which you can attach the Outex front glass port.
All of the above options can be found in the Outex online store in Shop By Parts
If you still have questions or need help contact our tech support team at firstname.lastname@example.org or (818) 583-7731.