Text and images by Hergen Spalink
Big-animal action is one of the areas of underwater imaging where mirrorless cameras provide a clear advantage with their ability to show a WYSIWYG rendering of the ever-present blue-water background. While you're still on the hook for nailing exposure of your foreground subject, you at least have a pretty good idea of what the background will look like before you press the shutter release.
Oceanic manta. F16, 1/200 at ISO 200, 28mm. WACP. The Dual Pixel AF of the EOS R helps nail focus on subjects as they rapidly change their distance to the camera.
The Canon EOS-R features a full-frame 30MP CMOS sensor and Canon's amazing Dual Pixel autofocus. The EVF is a 3.69M Dot OLED that features some very intelligent display processing. While most EVF equipped cameras have an Exposure Preview style setting, when working with external flashes the foreground will often appear too dark to allow good composition management. A workaround for Sony cameras was to assign the ability to disable the exposure preview to one of the many custom buttons. After using the Exposure Preview to dial in the ambient exposure of the image (the background), disabling it allows you to compose the foreground subject and make sure focus is correct. With the EOS-R, the Exposure Preview can be momentarily disabled for a preset duration with a half-press on the shutter enables the metering system. This makes nailing foreground composition and background exposure possible without any added button pressing.
This setting is in the Shooting Menu (the camera icon)>Tab 3>Metering Timer
The NA-R housing can be used with either the newer R-mount or more prevalent EF-mount lenses with one of Canon's various EF-R adapters. The adapter is contained within the housing which means those users who either also have or are moving from another N120 Canon DSLR system can use the same port and extension configurations for both systems.
White tip reef sharks on a ledge. F6.3, 1/80 at ISO 200, 28mm. The WACP has excellent corner sharpness, even at F6.3 as compared to a standard lens and dome port combination which, combined with a 0" minimum focus distance allows for creative use of depth of field.
The WACP or 0.36x Wide Angle Conversion Port is a natural fit for capturing great pelagic action. With full zoom-through and extreme corner sharpness even at wider apertures, the WACP is perfect for the variety of both subject size and available light conditions you find in Socorro.
White tip reef sharks. F5.6, 1/125 at ISO 200, 80mm. The full zoom-through of the WACP allows capturing establishing, medium and tight shots of a subject with a single lens.
When snorkeling and freediving with fast-moving mobula ray schools in Cabo San Lucas, the low profile of the WACP makes it easy to get into the right position and move quickly with your subject.
Mobula rays. F22, 1/160 at ISO 400, 28mm. High aperture and a moderately fast shutter speed creates a pleasing sun and freezes the fast moving school of rays.
Below are some additional images, all captured with the Canon EOS R with the WACP in the NA-R housing.
Galapagos shark. F16, 1/200 at ISO 200, 28mm.
The Boiler. F6.3, 1/100 at ISO 200, 28mm. Being able to use wider apertures allows for good foreground separation.
Bottlenose dolphins. F8, 1/125 at ISO 1600, 28mm. Dual Pixel AF and good higher ISO was essential for the often challenging light conditions in Socorro. This was a cloudy early morning dive.
Silvertip sharks. F8, 1/80 at ISO 400, 55mm. When sharing a scebe with multiple photographers, being able to zoom in is invaluable.
Yellowfin tuna. F8, 1/125 at ISO 400, 28mm.