Most action cameras are designed with a focal length of infinity, minimum focusing distance is usually limited to approximately 60 centimeters/2 feet; the footage will appear out of focus if the object is too close to the lens, and that’s why external wet lenses can push the boundaries and take action camera footage to the next level.
Wide-Angle Lenses
Though the majority of action cameras are equipped with ultra wide lens, its coverage underwater will dramatically narrow down due to different refraction ratio between air and water. External-mounting wide-angle lenses are designed to compensate for the narrowing field of view caused by the underwater light refraction to the native lens of the device.
The most common question we received is why do we need an additional wide-angle lens when the device already has a wide-angle setting? Here is the answer : With wide-angle lens installed, the minimum focusing distance would become approximately 10 cm/4 inches compared to the 60 cm/2 feet limitation of the native lens. This means if you use a wide-angle lens to capture large creatures at a close distance, in addition to expecting the creatures can be captured in the frame completely and avoid being cropped, the sharpness of the footage would be more appearing. Shorter distance would be also helpful to achieve a significant improvement of lighting effect.
Macro / Close-up lenses
The same principle also applies to macro/close-up lenses. Depending on the lens model, from +5 to +23 magnifications, each lens has its limited focus range, the focal length of some lenses can even reach 2 centimeters/0.79 inches, and the imaging results are amazing!
When diving, you may encounter small creatures of various sizes, so you should consider in advance which lens is suitable for diving scenarios. Generally speaking, we recommend starting with the +10 model, which is easier to get familiar with; ultimately lenses in the +15 to +23 range will be relatively better at taking good footages and achieving amazing results.
Filters
With the proper filter installed, underwater footage will look more vibrant. Simply put, if you are only relying on ambient light, adding a red / pink filter is the most basic upgrade solution to improve the color of underwater videos.
