A Revolutionary Lens for Underwater Video: The Nauticam WACP

By Lee Burghard June 2018

After having the opportunity to shoot the Nauticam Wide Angle Conversion Port (WACP) on a recent dive trip to Papua New Guinea I wanted to share my experience and thoughts on the WACP from the perspective of someone who shoots mainly underwater video.

So what makes the WACP such a revolutionary lens? Two main features really stand out to me...optical performance and versatility.

Optical Performance:

It's important to understand what the WACP is, how it works, and what makes it so unique from other options in the market. The WACP is water contact .36x wide-angle conversion lens that's been optically designed specifically for underwater imaging.  When used in front of the right lens, the end result is an extremely wide and incredibly sharp image.

4K Frame Grab Captured with Nauticam WACP and Sigma 18-50mm at 18mm f/11

For example, a 28mm full frame equivalent lens is altered from a 75º field of view to whopping 130º field of view.  Not only is the combination wider, but based on testing it's also sharper in both the corners and center of the image when compared to most traditional wide-angle rectilinear lenses behind a large dome port.

4K Frame Grab Captured with Nauticam WACP and Sigma 18-50mm at 18mm f/6.3

The other unique optical feature is the WACP's ability to focus extremely close, in fact nearly right off of the glass. By minimizing the distance between your lens and the subject you can greatly improve color, contrast, and sharpness in your images. In addition this capability makes it an ideal choice for close-focus wide angle shooting.

4K Frame Grab Captured with Nauticam WACP and Sigma 18-50mm at 50mm f/5.6

Due to the optical design of the WACP, you now have the ability to shoot with wider apertures.  Most of us know from experience that shooting a rectilinear lens, such as 16-35mm, at aperture much wider than f8 resulted in very poor corner sharpness and often an unusable image...even behind some of the largest dome ports.  With the WACP I was able to shoot at much wider apertures (f4 to f6.3) with very acceptable sharpness and image quality. For shooting in low light conditions or when you want to create a shallow depth of field behind subjects this unique ability offers some major advantages.


The WACP is not only limited to shooting a 28mm full frame equivalent fixed focal length, in fact it is designed to allow full zoom through capability across a whole range of focal lengths above 28mm while maintaining sharpness.  This is perhaps where the WACP becomes most interesting.

For those of us using cinema, DLSR, or mirrorless cameras w/ interchangeable lenses, we do not have the luxury of swapping between several lenses underwater to capture a variety of angles on a wildlife subject like many "topside" shooters would. We have to pick a lens - in my case say a Canon 11-24mm, 16-35mm, or a 24-70mm - and stick to that during the entire dive. Any lens changes have to be made at the surface and capturing wide, medium, and close up shots of subjects typically means multiples dives with multiple lenses. The WACP however changes this scenario.

4K Frame Grab Captured with Nauticam WACP and Sigma 18-50mm at 18mm

4K Frame Grab Captured with Nauticam WACP and Sigma 18-50mm at 50mm

Due to the crop factor while recording 4K video on the Canon 1DX MKII camera & Nauticam housing I was using, I choose to use a Sigma 18-50mm F2.8-4.5 DC OS HSM crop sensor lens. When combined with the WACP this provided me with an approximate 130 degree field of view at the wide end of the lens while still have a great deal of zoom ability for tighter shots.  When you account for the WACP's close focus ability, I now had a very versatile lens combo to work with. The turtle sequence in the video above is a good example of this, where you can see wide, medium, and close up shots of the turtle...all of which were captured during the same dive.

That Sigma 18-50mm and WACP essentially replaced another 2-3 lenses that I would usually have to lug around on a trip, and saved me the hassle of having to continually swap lenses during my surface intervals. Aside from my 100mm macro lens, this was all I shot for the entire trip.

4K Frame Grab Captured with Nauticam WACP and Sigma 18-50mm at 18mm


Due to it's the versatility and optical performance the WACP is an excellent option for any professional or enthusiast underwater video shooter to consider. The WACP is currently compatible with a large variety of lenses and sensor sizes for cinema, DSLR, and mirrorless cameras. More combinations are currently being tested and you can contact us directly for recommendations specific to your equipment and needs, we're here to help!