Wet lenses are a fundamental accessory for underwater photography. These diopters and dome lenses can be used on compact, mirrorless and compact cameras, modifying the camera lens field of view to shoot small macro subjects and large wide-angle scenes.
This article and video tutorial are presented by:
Macro Diopters and Wide-Angle Wet Lenses
Wet Lens Basics
So what are wet lenses? Underwater wet lenses are used to modify your camera lens field of view to capture better photos of large and small subjects.
They sometimes referred to as water contact optics.
Macro diopters are used to magnify small subjects. Since most cameras can shoot true 1:1 macro photos (reproducing a subject in actual size on the image sensor), a diopter allows the camera to shoot super macro photos, where the subject is magnified beyond true size on the image sensor.
Wide-angle wet lenses, often called wide-angle dome lenses or wide-angle conversion lenses, expand the field of view of the camera lens. This wider field of view is ideal for shooting larger subjects.
Mounting a Wet Lens to your Camera
Macro and wide-angle wet lenses generally use 52mm or 67mm threads to attach the lens to the camera. SeaLife makes a DC adapter that allows you to press on and pull off the lenses to the port of the DC2000 camera, which is much faster than screwing on and screwing off a wet lens.
These thread mounts are universal, meaning the diopter can be used on any camera with the same threading. Many compact housings use 52mm, while most mirrorless and DSLR housing ports use 67mm threads.
SeaLife makes a step-up adapter to use the DC-Series Super Macro Lens (52mm) on 67mm threading, and also a step-down adapter so that you can use a 67mm diopter on the DC2000.
All this is to say that your wet lens investment is adaptable to most camera systems. The only exception is that some wide-angle wet lenses are designed specifically for certain lenses. Your local dive shop or underwater camera retailer can discuss these differences in detail.
Some manufacturers make flip adapters, as shown in this article’s tutorial video, which allow you to quickly flip a wet lens on and off the front of the camera housing port.
What is a macro diopter? Macro diopters are used to magnify small subjects when shooting underwater photo and video.
Since most cameras can shoot true 1:1 macro photos (reproducing the true size of the subject on the image sensor), a diopter allows the camera to shoot super macro photos, where the subject is magnified beyond true size on the image sensor.
Benefits of Using Macro Diopters
In addition to magnification, the benefit of a macro diopter is that you can focus the camera from a much shorter distance. In other words, you can achieve focus on the subject from a much closer distance to the subject. The SeaLife DC2000 lens, for example, as a minimum focus distance of 3.5″ (9cm). When you pop on the DC-Series Super Macro Lens that minimum focus distance drops to just 1.5″ (4cm).
This shorter minimum focus distance has two great benefits. First, you are closer to the subject, helping to fill the frame. Second, you are shooting through less water, which delivers a crisper, clearer image with bolder colors, stronger contrasts and other optical benefits.
I recommend a macro diopter to every underwater photographer who already has a strobe or video light for their system.
Wide-Angle Wet Lenses
What are wide-angle wet lenses? Wide-angle wet lenses expand the field of view of your underwater camera lens. This is very useful for getting close to large subject while still composing to see the entire scene.
For example, adding the SeaLife .75x Wide Angle Conversion Lens to the DC2000 expands the field of view by 33%. Adding the 0.5x Wide Angle Dome Lens expands the field of view by 100%!
Wide-angle wet lenses are fairly universal, but many are designed with specific camera systems in mind. Be sure to discuss the best options for your camera with your local dive shop or underwater camera retailer.
Benefits of Wide-Angle Wet Lenses
There are two benefits to that result from using a wide-angle wet lens. First, the wide field of view allows you to get close to your subject while still seeing the full scene (think of a shipwreck, whale, or reefscape). This not only emphasizes the subject / focal area in the composition, but minimizes the water between camera and subject. As a result, the image will be crisper and clearer, delivering better color.
The second benefit is that your strobes or constant light have greater power when closer to your subject. Light falls off dramatically underwater, so the closer your light source to the subject, the less water the light must travel through, and less degradation of the light. This also delivers better color, contrast, and definition in your images. And since you’re close, you have more room for creative strobe positioning to create the perfect lighting effect.
Wet Lens Photo Tips
Tip #1: Burp your wet lens when you enter the water!
These water contact lenses are designed to have water in the slim space between the camera housing port and the back of the wet lens, but sometimes air can get trapped in that space on the surface.
By removing your wet lens and waving away any errant bubbles once you’ve descended for your dive, you ensure that water fills this space (for best optics) and that no bubbles appear in your images.
Tip #2: Attach your lenses with a lanyard!
This tip specifically applies to the convenient bayonet style mount for wet lenses. This mount makes it quick and easy to pop lenses on and off the camera housing for quick switches between wide-angle and macro, but it also presents an opportunity for the lens to get knocked off accidentally.
This is most common when entering the water or during a safety stop at the end of a dive. Be sure to use a lanyard to secure your lens.
Tip #3: Dial-in your buoyancy when using a macro diopter!
Macro diopters not only magnify small subjects, but also magnify small movements of the camera (think of a telescope). You need to have full control of your buoyancy in order to hold the camera steady while focusing on the subject. I always recommend using a macro/muck stick.
A nice side effect of buoyancy control is that you will be less likely to damage the reef or kick up a cloud of sand that will earn scowls from other photographers in the group.