Today I’m going back to one of the basics topics in underwater photography, wide-angle lenses.
One of the most repeated sentences when coaching underwater photographers is “get closer” and there is a very simple reason. Water is much denser than air. It will absorb and dissipate light causing the image quality and contrast to rapidly drop. The further away the subject is, the poorer the image will be. This problem is dramatically increased if the conditions are not optimal, sediment or plankton will reduce the image quality.
Why we use wide-angle lenses
In order to regain the sharpness and contrast we want in our pictures, the only solution is to get as close as possible. This will reduce the amount of water between the lens and the subject. And here is where the wide-angle lens comes into play.
A wide-angle lens in land photography is considered any lens with a focal length shorter than 35mm (or equivalent). The shorter the focal length is, the greater the angle of view of your picture.
By increasing the angle of view of your camera you can reframe your picture from a shorter distance.
Another reason to get closer is to ensure the light of your strobes reaches the subject. Even the most powerful flashguns have a working distance of no more than 2 meters.
Wide angle options
When looking at wide angle options you have two main groups. Fish-eye and rectilinear.
Fisheye lenses have a greater angle of view, most of them can give you up to 180 degrees of diagonal coverage. This means that the camera will capture an image covering around 180 degrees of view from one corner to corner. To achieve this the lens will distort the image giving it a characteristic “Fish Eye” effect, hence the name.
These lenses are an excellent option for underwater photography. They allow us to focus incredibly close to the subject maintain image sharpness as well as offering a superb depth of field (the area of the image in focus from the foreground to the background)
Fish-eye is my first choice for wreck and general wide angle photography.
Rectilineal lenses do not offer the same angle of view and do not create the same level of distortion. The depth of field is not as good as what a fish-eye lens but good enough for most situations.
A couple of things worth mentioning here is the corner sharpness and the ability to focus close to the camera. Rectilineal lenses can suffer from softens in the corners of the frame, particularly when shutting at wide apertures and if the dome port is not correct.
Because of the way the optics work, rectilinear lenses will struggle to focus when a subject is very close to the dome. This will limit their ability to shoot close-focus wide-angle images.
There is one situation in particular when these lenses are by far the best option. Shutting sharks and other pelagic animals. These are generally speaking very shy rarely come close enough to use a fish-eye lens, the massive field of view will make impossible to fill the frame with your subject. The narrower view of a rectilinear wide-angle is much better suited to photograph these subjects.
For my next Shark Quest Photography trip to the Southern Red Sea, I will pack a rectilinear zoom lens. This will give me the ability to zoom in to fill the frame even when the sharks decide to maintain a cautious distance.
Prime or zoom Wide-angle lenses
You may have heard photographers talking about Prime and zoom lenses. The difference between this two kind of lenses is simple, prime lenses have a fix-focal length while zoom ones allow you to vary it. This means prime lenses have less optical elements, therefore, the image quality is less compromised and produce sharper images. This distinction applies to all lenses, not only wide angle.
Saying this, the image quality of modern lenses, even zoom ones is remarkably good and many photographers, including myself, are very happy with the results.
What about if I use a compact camera?
For compact cameras users, the options of fish-eye and wide-angle are more limited but none the less available. There are many manufacturers that make conversion wet lenses. These lenses attach to the housing in front of the lens and increase de angle of view of the camera lens. These lenses are not cheap and as is the case with DSLR and Mirrorless cameras, the more you are willing to spend, the better the image quality will be.
Most wet lenses are designed to work with the camera lens set to a specific focal length. usually 28mm or equivalent. Even if you can zoom your camera, I would strongly advise against it. The image quality, especially in the edges of the picture will be literally destroyed.
Recently some manufacturers came up with a wet wide angle lens for compact and mirrorless cameras that offers an incredibly wide field of view and allow full zooming capabilities. This is an excellent option for shutting pelagics such as hammerheads.
Join me on my next trip to the Red Sea, the Shark Quest Photography onboard the recently refurbished Hurricane. As part of the workshop, I will be talking a bit more in-depth about wide-angle lens options and if It is possible you are more than welcome to try one of my lenses.