When shown someone's underwater pictures and asked how to improve them the most common thing the Blue Duck Team find themselves saying is 'get closer'. Reducing the distance between you and your subject means less water between the camera and what you are photographing. Because of the effect of water and the particles floating in it on light, the less between the camera sensor and the subject means clearer, crisper looking images.
What a wide angle lens allows you to do is frame the same subject in your picture but from a much shorter distance.
The images below were both taken with the same Canon Ixus camera without and then with an Inon wide angle wet lens. The framing is roughly the same but the distance to the subject when using the wide angle lens was greatly reduced.
When choosing a camera and underwater housing for it to go inside, the ability to add a wide angle lens should be high on your list of features. Not all setups are created equally. Mirrorless cameras and DSLR's have the ability to be fitted with wide angle or fisheye lenses on the camera itself and a good lens will give you startling results. When looking for a housing for one of these interchangeable lens systems you should look carefully into whether the housing system allows you to fit different ports to the housing and if so what lenses are supported by these ports.
The image below was taken with an Olympus EM10 MkII camera with an 8mm Olympus fisheye lens in a Nauticam housing, the same setup as Anne is holding in the picture.
With compact cameras you are limited to using wet wide angle lenses which fit on the outside of the housing. Be aware that not all camera and housing combinations function the same when it comes to adding wide angle wet lenses. Many compact cameras, especially the higher end ones have long zoom lenses, for example the Canon G7X MkII has a 24-100mm. What this means is that to accommodate the full movement of the lens through its focal length range the port on the housing must be deep and wide. This interferes with using a wide angle lens, necessitating using poorer substitutes which often take the form of push-on domes rather than genuine wide angle wet lenses with glass elements. It also usually means zooming the lens in to avoid vignetting at the corners of the image.
If you have any notion of progressing in your underwater photography it's worth thinking seriously about what wide angle lens the housing and camera will support. This doesn't always come down to the most expensive being the best. For example the G9X MkII in a Fantasea housing will support a high end wide angle lens with a 67mm thread and while the more expensive G7X MkII camera needs to be placed in the more expensive Nauticam housing with a special additional Short Port in order to use the same wide angle lenses as its cheaper cousin.
Wide angle wet lenses are not the sole domain of compact camera users, they also perform well with interchangeable lens cameras when used with kit lenses in flat, threaded ports. The above image was taken using an Olympus EPL-3 in an Olympus housing fitted with an Inon wide angle wet lens.
Having the ability to remove a wide angle lens and fit a macro lens during a dive is seen by many photographers as an advantage. It reduces the risk of infuriating moments when diving with a macro lens and you see a wide angle subject and vice-versa.
There are a number of excellent wide angle lenses currently on the market including offerings by Inon, Fantasea and Nauticam. Inon in particular specialise in making wet lenses and adapters to work with many of the branded camera housings. The image above was taken using a Canon S95 in a Canon housing fitted with an Inon lens mount and Inon wide angle wet lens. We sell all the above brands of wet lenses and can help match your current camera to a lens or give you advice on which camera and housing pairs are a good option both in the new and used markets.