GoPro cameras have come a long way since they were first introduced in 2004. Their latest model at time of writing is the Hero 10, an action camera powerhouse capable of 5.3k resolutions at 60fps and even 120fps at 4k! Such high frame rates and resolutions are unheard of in all but the latest high end digital prosumer or professional cinema cameras. It’s incredible that it’s now available in a tiny action camera offering amazing image quality.

While I have used GoPro cameras occasionally as an underwater cameraman, the limited field of view options always meant I would never use it as a primary stand alone camera during dives. Superview, although wide enough, will give very distorted corners underwater with a pin cushion effect. Wide mode is best for underwater work with the least distorted image. However once the camera is underwater, the field of view (FOV) narrows from 130° (Wide mode) on land to about 90° due to refraction. While it is still usable, in my humble opinion, 90° degrees simply isn’t wide enough for a lot of underwater applications and doesn’t mimic any common lenses used in underwater videography.

The AOI UWL-03 wet lens manages to solve this issue spectacularly.


AOI Limited

Founded in Hong Kong in 1994, AOI entered the camera industry, manufacturing compact film cameras and disposable cameras. They also started manufacturing underwater housings. Years of expertise in the underwater housing market led AOI to become one of the largest original equipment manufacturers for underwater equipment with clients such as Olympus.

AOI has a long history and experience in making OEM underwater housings

In 2014, AOI began manufacturing and marketing underwater imaging equipment under their own brand with a particular focus on underwater optics while continuing to OEM for other companies.

AOI today


AOI UWL-03 wet lens

The UWL-03 wet lens is a 0.73x underwater wide angle conversion lens. While it was designed with the GoPro range of cameras in mind, it should work with most action cameras. The lens comes standard with a quick release bayonet mount system (QR2), which is also compatible with Inon’s AD mount. The unit comes very well protected and includes a rear cap cover, neoprene dive cover and a larger neoprene cover for additional protection during transportation. This is important as the front dome element is polycarbonate with a hard coating that can still scratch easily. Kudos to AOI for including everything needed to protect the dome. The rest of the internal lens elements are constructed with 4 glass elements in 4 groups with multiple layers of anti reflective coatings. The body and the lens hood are made of aluminum and are available in both black and white!

UWL-03 lens and included protective covers
The lens comes very well protected with dual neoprene lens covers for travel

The quick release mount base (QRS-02) is sold separately or can be bought as a package with the lens. It is easy to use and provides a positive lock to any original GoPro housing. Keep in mind that this attachment system is only designed for original GoPro housings. The QRS-02 mount base package comes with a pistol grip, a Hero 9/10 compatible mounting base and 2 adapters to convert the base for Hero 8 or Hero 5/6/7 original underwater housings.

GoPro Hero 8 housing with the QRS-02 set

For everything else, AOI also sells adapters to change the mount to M55, M52 or M46 threads. For my use, I actually changed my mount to an M52 thread and used a step ring to increase the ring size to M67. This fits the diopter holder on my Hugyfot Vision XS GoPro housing. A review of this housing will be in the next article! 

UWL-03 with the M52 adapter installed for M52 threads (Adapter sold separately)
UWL-03 mounted on my Hugyfot Vision XS Hero 10 housing

Underwater performance

The AOI lens gives a magnification of 0.73x and widens the view underwater to 140° and 150° on land. In addition, the close focus of the lens is drastically improved. All of these points are really important characteristics required by underwater photographers or videographers.

WIth the lens mounted, corners were sharp and there was no pincushion distortion that’s visible. You can see in the video below that I managed to get almost within touching distance of a puffer fish. Details were still sharp and in focus. The UWL-03 allows for good close focus wide angle shots.

My 2 ‘dive days at SIpadan Island were extremely productive. I saw barracudas vortexes, massive schools of Jacks, bumphead parrotfish and too many turtles to count. The lens worked flawlessly and I really appreciated the wider field of view and close focus. Combined with the high resolution and high frame rates capable with the GoPro Hero 10, I realized I didn’t miss my larger cameras at all! In fact, I will now be using this setup for my next few personal trips, reserving the production camera only for work assignments! It’s incredibly liberating to be able to travel light for dive trips!

Pricing and availability

With an MSRP of US$199, this lens is a must for anyone planning to use their GoPro as a serious underwater imaging device. Dive-C is the official distributor for AOI products in Malaysia. You can also visit the AOI website to find a local dealer near you.

Next article coming soon will be about using the Hugyfot Vision XS GoPro Hero 10 housing. The advantages and issues faced (and overcome) using the Hero 10 underwater.

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