Introduction to Mirrorless Cameras for Underwater Photography

What is a mirrorless camera?

• High-end compact alternative – mirrorless cameras are marketed as an alternative to high-end compact cameras, and are designed for amateur photographers. “Great image quality in a small size”.

• Live View – these cameras have live view like a compact camera, not an optical viewfinder like a dSLR

• No Mirror – the lack of an internal mirror allows the camera bodies to be a smaller size. FYI –the mirror in a dSLR, in conjunction with a pentaprism, reflects the image through the optical viewfinder. The mirror flips out of the way when a photo is taken.

• Interchangeable lenses – unlike compact cameras, mirrorless cameras support different lenses

Mirrorless camera features & benefits

• Larger Sensor - the sensor size of a mirrorless camera is much larger than a compact camera, resulting in more dynamic range, and less noise when using high ISOs. Greater depth of field than a dSLR at the same aperture

• Contrast detection for focusing. These cameras focus more like a compact than like a dSLR, which uses the quicker phase-detection

• Smaller lens size – lenses specifically designed for mirrorless cameras are often much smaller than equivalent dSLR lenses

• HD Video with autofocus – the video from these cameras is quite nice

• Kit lens with small zoom range. Some high-end compacts will give you a much larger zoom range for telephoto, because it is easier to make lenses with a large focal range for compact cameras

• Lens mounts are available for many different “old” lenses, although they may not autofocus

Types of Mirrorless Cameras

• Micro-four thirds - These are made by Olympus and Panasonic, and are the most popular category.

• Sony cropped sensor - Sony cameras like the Sony A6500 and A6300 are small like the micro-four thirds camera, and have a reputation for both excellent stills and video, and ease of use.

• Sony full-frame - The A7R II and A7R III are professional full-frame cameras that can compete with dSLRs in many areas.

Olympus E-PL2 Micro Four Thirds camera

Micro Four Thirds Cameras

The Olympus OM-D E-M1 II, E-M5 II, E-PL2, E-PL3, E-PM1, E-PL5, OM-D E-M1, E-M5, E-M10, Panasonic GH5, GX8, GX1, GF2 & GH3/GH4 are examples of what is called Micro Four Thirds cameras.

What is a micro four thirds camera?

Most (but not all) mirrorless cameras are micro four thirds cameras. The name refers to the a standard created by Olympus and Panasonic, and also to the dimensions of the sensor in the cameras. You can read more here.

These cameras are becoming a popular niche in underwater photography. All share the same size Micro Four Thirds sensor, and have the same lens mount. This means that a lens for the E-PL2 can be used on the GF2/GH2, and vice-versa.

The sensor size is 6-9 times the size of a compact sensor, but half the size of a cropped sensor dSLR. Olympus dSLR cameras like the E520 and E5 share the same sensor, but a different lens mount than a Micro Four Thirds camera.  Sensor size is 18mm x 13.5mm; 4x3 aspect ratio.

Some popular micro four thirds cameras:

• Olympus OM-D E-M1 Mark II - the top of the line Olympus model

• Olympus OM-D E-M5 Mark II - same image quality as the E-M1 II at a lower price

• Panasonic GH5 - the top of the line Panasonic model, capability of professional level video

Older Models

• Olympus E-PL2 – 12 megapixels, discontinuied. Popular choice in the US for a mirrorless camera.

• Olympus E-PL1 – Discontinued. Almost the same as the E-PL2.

• Olympus E-PL3 - 12 megapixels, discontinued. Replaces the E-PL2, with a new sensor and faster auto-focusing

• Olympus E-PL5 - 16 megapixels, $499, same sensor as the OM-D E-M5

• Olympus E-PL7 - newest of the PEN line, $699, read the full Olympus E-PL7 review here

• Olympus E-PM1 - 12 megapixels, discontinued. Less expensive version of the E-PL3

• Olympus OM-D E-M1 - read the full Olympus OM-D E-M1 review here

• Olympus OM-D E-M5- 16 megapixels, $999 for body only. High-end choice.

• Panasonic GX1 - 16 megapixels, discontinued. Was a good high-end choice.

• Panasonic GF2 – 12 megapixels, discontinued. Smallest mirrorless 4/3rds camera out there. Touch screen controls instead of dials.

• Panasonic GF1 – top pick by Thom Hogan, http://www.bythom.com/compactmirrorless.htm  but hard to find.

• Panasonic GH2 – 16 megapixels, discontinued has great hi-def video quality of mirrorless cameras, best image IQ, very fast auto-focus. Larger sensor size.

• Panasonic GH3/GH4 - these cameras takes some of the best professional video out there and are top picks for stills and video. You can see some sample Panasonic GH4 underwater video here.

Mirrorless Camera Underwater Housings

• Olympus: By far the most popular underwater housings are the Olympus housings for the E-PL1, E-Pl2, E-PL3, E-PL5, E-PL7, E-PM1, and E-M1 Mark II considered a great value

• 10-bar: Makes mid-range housings for the E-PL1, GF-1, GF-2 and GH-1

• Ikelite also provide a great value housing, including the newly release Ikelite Sony A7R III Housing.

• Recsea makes top of the line housings for the E-PL1, GF-1, GF2, GH-1, NEX-5, NEX-5N, NEX-7 and GH-2.  Most recently, the  Olympus OM-D E-M1  

• Nauticam makes housings for almost all of the mirrorless camera models, including the Nauticam Olympus OM‑D E‑M1 Mark II Housing, the Nauticam Panasonic GH5 Housing, and the Nauticam Sony A7R III Housing.  

• Aquatica make a variety of aluminum housings including the Olympus OM-D E-M1 and Olympus OM-D E-M1 Mark II, the Panosonic GH5 and the Sony A6500 and A6300 and the soon to be released, Sony A7R III.

• Sea & Sea makes another quality aluminum housing and has released the Sea & Sea Sony A7R III Housing.

• Acquapazza make NEX-5 & NEX-5N housings, all considered good quality.

You can view all current mirrorless housings here. At 47% off, the E-M5 Mark II bundle sale is the best value for a mirrorless housing.

Where to Buy

You can call the staff at Bluewater Photo for more advice on mirrorless cameras and mirrorless camera housings.

For the latest recommendations, view their best mirrorless cameras for underwater guide.

Part II - Mirrorless camera Lens Selection

Lens selection is very important when looking at mirrorless cameras, please read out guide to the best micro four thirds lenses for underwater photography. A guide to the best Sony lenses will be coming soon.

Further Reading

• 5 Reasons to go Mirrorless

• Olympus E-PL1 review

• Overview of Underwater Photography Equipment

• Learning how to get sharp images underwater

• Panasonic 8mm fisheye lens review

• Olympus OM-D E-M5 review