Sony has recently announced three new cameras that bring significant upgrades to their existing lineup. The Sony a7R II, RX100 IV, and RX10 II each offer improvements tailored to meet the needs of photographers and videographers, including those specializing in underwater imagery. The RX100 series has been a favorite among underwater photographers, while the a7R series continues to attract those who seek high resolution and full-frame performance.
This review covers the key specifications of each model, highlighting what is new compared to previous versions. Hands-on underwater testing will provide further insights as soon as compatible housings become available.
Sony a7R II Camera Overview
The Sony a7R II features a 42-megapixel full-frame Exmor R CMOS sensor with back-illumination technology. This sensor delivers impressive image quality with high resolution and improved sensitivity, expandable up to ISO 102,400. The camera includes a BIONZ X image processor that supports advanced processing capabilities.
The model incorporates a 5-axis SteadyShot INSIDE image stabilization system, allowing for sharper images even in challenging conditions. Autofocus has been upgraded to 399 phase-detection points, enabling fast and accurate focusing at up to 5 frames per second.
Video capabilities are strong with internal 4K recording in the XAVC S format at 30 or 24 frames per second. Additionally, the camera supports S-Log2 Gamma for extended dynamic range, beneficial for post-processing. Built-in Wi-Fi with NFC simplifies image transfer and remote control.
Comparing the Sony a7R II with Its Predecessor
According to official information, the a7R II is the first interchangeable lens camera to use a back-illuminated full-frame Exmor R CMOS sensor. This sensor achieves approximately 42.4 effective megapixels, offering high resolution and sensitivity. Autofocus response is reportedly 40% faster than the original a7R, thanks to the expanded phase detection AF points.
The a7R II was scheduled to ship in August 2015, marking a significant step forward for full-frame mirrorless cameras, especially for users requiring detailed image capture and professional video features.
Sony RX100 IV Camera Overview
The Sony RX100 IV is equipped with a 20.1-megapixel 1.0-type Exmor RS CMOS sensor, featuring a stacked design that includes a DRAM chip for faster image readout. This sensor dramatically improves shutter speed and burst shooting capabilities.
The lens is a ZEISS Vario-Sonnar T with an aperture range of f/1.8 to f/2.8 and a focal length from 8.8 to 25.7mm. Its minimum focusing distance is just 0.17 feet, allowing for close-up photography. The camera incorporates the BIONZ X image processor, enhancing overall performance.
Video features include 4K recording and super slow-motion video at up to 40 times slower than normal speed. Burst shooting reaches up to 16 frames per second. The RX100 IV also has a front control ring that aids in adjusting settings underwater and a tiltable LCD screen with 180 degrees of rotation for flexible framing. Like the a7R II, it offers built-in Wi-Fi and NFC for connectivity.
Advances in the Sony RX100 IV Compared to the RX100 III
The main improvement over the RX100 III is the new Exmor RS CMOS sensor with its DRAM chip, enabling ultra-fast data processing. This allows for higher burst rates, 4K video capabilities, and super slow-motion capture at frame rates reaching 960 frames per second.
The RX100 IV’s release date was July 2015, and it has since been regarded as one of the top compact cameras for underwater use due to its combination of image quality, speed, and portability.
Sony RX10 II Camera Overview
The Sony RX10 II caters to those seeking an all-in-one camera with a versatile zoom lens ideal for both underwater and topside shooting. It features a 20.2-megapixel 1.0-type Exmor RS CMOS sensor with a stacked design, paired with a ZEISS Vario-Sonnar T lens that has a constant aperture of f/2.8 and a focal length ranging from 8.8 to 73.3mm.
Performance is enhanced by the BIONZ X processor, supporting 4K video recording and super slow-motion video up to 40 times slower than standard playback. Burst shooting reaches 14 frames per second. Connectivity options include built-in Wi-Fi and NFC.
Improvements in the Sony RX10 II Compared to RX10
The key upgrade over the RX10 is the sensor design, incorporating the DRAM chip for fast readout speeds. This facilitates better electronic shutter performance, enabling higher burst rates and advanced video features like 4K capture and ultra slow-motion recording.
The RX10 II was also slated for release in July 2015 and offers a highly capable solution for photographers wanting a rugged, versatile compact camera suitable for underwater and surface shooting scenarios.
Detailed Specifications and Features of the Sony a7R II
The Sony a7R II represents a major advance in mirrorless camera technology, especially for underwater photographers who demand the highest image quality and professional features. It's a 42.4-megapixel full-frame sensor that captures exceptional detail, making it suitable for large prints and cropping flexibility. The back-illuminated sensor design improves light gathering efficiency, which results in better performance in low-light conditions commonly encountered underwater.
The camera’s ISO range, expandable up to 102,400, gives users the flexibility to shoot in dim environments, such as caves, wrecks, or deep dives, without excessive noise. This is a significant advantage where lighting is limited and artificial light sources can only go so far.
The 5-axis image stabilization system compensates for hand shake and motion in five different directions. Underwater, where buoyancy and movement often affect stability, this feature helps produce sharper images without the need for extremely fast shutter speeds. It also enhances video stability during handheld 4K recording.
Autofocus in the a7R II is a highlight, with 399 phase detection points spread across a wide area of the frame. This wide coverage allows for quick, precise focus tracking on moving subjects like fish or marine mammals. Autofocus speed is reportedly 40% faster than the original a7R, minimizing missed shots of fleeting moments. The camera also includes contrast detection points to assist in low-contrast situations.
For video shooters, the a7R II offers internal 4K recording with full pixel readout and no pixel binning, which results in higher resolution and less moiré. The S-Log2 Gamma profile provides extended dynamic range, useful for underwater scenes with strong contrast between sunlit surfaces and shaded depths. The ability to shoot 4K internally without an external recorder simplifies underwater video rig setups.
Connectivity options like built-in Wi-Fi and NFC facilitate easy transfer of images to mobile devices for quick sharing or remote camera control, though underwater use of wireless functions requires the camera to be out of the housing or in an environment where signals can reach.
The camera’s magnesium alloy body construction ensures durability and resistance to harsh conditions. For underwater use, compatible housings offer full control of the camera’s functions, but the size and complexity of the a7R II system mean the rig can be bulkier compared to compact cameras.
Strengths and Considerations of the Sony a7R II for Underwater Photography
The a7R II’s high-resolution sensor is a double-edged sword. On one hand, it provides incredible detail, allowing photographers to crop tightly or produce large prints without losing image quality. On the other hand, higher resolution sensors demand better lenses and a very steady shooting technique to avoid softness from camera shake or lens aberrations. This is particularly important underwater, where water movement, buoyancy, and lighting conditions add complexity.
Its 5-axis image stabilization partially mitigates this by reducing blur from motion, allowing for slower shutter speeds. However, for very sharp images of fast-moving subjects or in challenging conditions, external strobes and fast lenses are still highly recommended.
Battery life on the a7R II is decent but shorter than many DSLRs, so underwater photographers should carry extra batteries for extended dive sessions.
The camera’s dynamic range and 4K video capabilities offer creative flexibility for underwater videographers. However, shooting 4K requires fast memory cards and careful workflow for post-production.
The autofocus system’s speed and accuracy make it suitable for subjects in motion. Yet, autofocus underwater can still be challenged by low contrast and low light, so manual focus skills remain valuable.
Detailed Specifications and Features of the Sony RX100 IV
The Sony RX100 IV, while much smaller and lighter than the a7R II, packs impressive technology into a compact body. Its 20.1-megapixel 1.0-type Exmor RS CMOS sensor with DRAM chip is a standout, enabling incredibly fast readout speeds that support high burst shooting rates and advanced video features.
The lens, a ZEISS Vario-Sonnar T, provides a versatile zoom range equivalent to approximately 24-70mm in 35mm terms, with a bright aperture from f/1.8 to f/2.8. This allows for better low-light performance and pleasing background blur effects even in a compact camera.
Close focusing distance of 0.17 feet allows for detailed macro shots without additional equipment, an attractive feature for underwater photographers interested in small subjects like nudibranchs or crustaceans.
The RX100 IV offers 4K video recording internally, an impressive feature for such a compact camera. It's super slow-motion mode can capture video up to 960 frames per second, which can produce dramatic slow-motion effects useful for capturing fast underwater movements.
The front control ring adds tactile control over settings such as aperture or ISO, which can be beneficial underwater where touchscreen operation may be limited by gloves or housing buttons.
The 180-degree tiltable LCD screen is useful for composing shots from awkward angles, including close to the substrate or for selfies.
Connectivity options mirror those of the a7R II, with Wi-Fi and NFC for easy sharing and remote operation.
Real-World Image Quality and Performance of the Sony a7R II
The Sony a7R II delivers exceptional image quality that meets or exceeds many professional DSLR cameras. It's a 42.4-megapixel full-frame sensor that captures extraordinary detail, making it ideal for underwater photographers who want to produce large prints or crop images without sacrificing resolution. Color reproduction is natural and accurate, with a strong dynamic range that preserves highlights and shadows in challenging underwater lighting conditions.
Low-light performance is a major strength of the a7R II. The back-illuminated sensor design and high maximum ISO allow shooters to capture sharp images in dim environments, such as deep water or caves, where ambient light is scarce. Noise control remains impressive up to ISO 3200 and usable even beyond that, offering greater flexibility without resorting to excessive strobes.
Autofocus performance is robust and fast, even in low-contrast underwater scenes. The combination of 399 phase-detection points and 25 contrast-detection points provides comprehensive coverage and reliable tracking of moving subjects such as fish or turtles. The eye autofocus feature further enhances focus precision on animal subjects, a welcome tool for underwater portraiture.
The 5-axis image stabilization allows slower shutter speeds while maintaining sharpness, compensating for diver movement and the natural instability underwater. This makes handheld shooting more feasible, especially in macro or low-light conditions where tripods or steady surfaces are unavailable.
Color reproduction is vibrant and accurate, with good contrast and tonal gradation. The camera’s JPEG engine produces pleasing images straight out of the camera, although RAW capture is recommended for greater post-processing control.
Autofocus and Usability Underwater
Autofocus speed and reliability are critical for underwater photography, where subjects can be unpredictable and movement can be sudden.
The a7R II’s hybrid autofocus system combines phase detection and contrast detection for fast and accurate focusing. Its wide AF coverage allows for flexible composition without compromising focus tracking. Eye AF and focus peaking assist with precise focusing, especially useful for macro or portrait shots. Underwater housings with external controls provide good access to focus settings.
The RX100 IV’s autofocus system benefits from the fast sensor readout and performs well in typical underwater conditions. Its small size and control ring allow quick adjustments to focus and exposure. However, the compact form can be more challenging to handle with gloves or bulky housings.
The RX10 II’s larger body and ergonomics make it comfortable to hold and operate underwater. Its autofocus is reliable and fast, supporting subject tracking in a variety of conditions. The zoom lever and buttons are well-positioned for use in housings, offering intuitive control.
Practical Usability and Handling Underwater
Handling and usability of cameras underwater depend heavily on housing design and ergonomics.
The a7R II requires a professional-grade housing that provides full control of the camera’s functions. These housings tend to be larger and heavier, reflecting the camera’s size and capabilities. While this rig can be bulkier, it offers superior control for photographers accustomed to DSLR-like operation. Its robust build and control layout make it suitable for serious underwater photographers who value manual settings and customization.
The RX100 IV’s compact size makes it highly portable, but housing designs must balance protection and access to controls. Some housings integrate external rings and buttons for adjusting aperture, shutter speed, and focus. Its size favors travel and spontaneous dive photography, though it can be more difficult to grip securely.
The RX10 II’s body size and grip design facilitate comfortable handling underwater, even with gloves. Housing designs for this model typically provide ergonomic controls for zoom, focus, and shooting modes. It's all-in-one zoom lens reduces the need to change ports or lenses underwater, simplifying dive shoots.
Battery Life and Storage Considerations
Underwater photography sessions often require extended shooting times, so battery life is a crucial factor.
The a7R II offers moderate battery life, with approximately 340 shots per charge. Photographers should carry multiple batteries for dive days or extended shooting sessions, especially when shooting video or in cold water that can reduce battery efficiency.
The RX100 IV has a smaller battery due to its compact size, providing around 280 shots per charge. Backup batteries are advisable for diving trips to avoid missed opportunities.
The RX10 II benefits from a larger battery, delivering about 400 shots per charge, making it the most suitable for longer sessions without swapping batteries.
All three cameras use high-speed memory cards to support fast burst shooting and 4K video recording. Ensuring sufficient card capacity and speed is essential for uninterrupted shooting.
Strengths and Considerations of the Sony RX100 IV for Underwater Photography
The RX100 IV’s compact size and advanced sensor make it an excellent choice for divers who want a lightweight rig that can still deliver high-quality images and video. It's fast sensor readout minimizes rolling shutter effects, which are common in fast-moving underwater scenes.
Its lens provides a versatile zoom range that covers wide-angle to short telephoto, useful for capturing a variety of subjects. However, the zoom range is more limited compared to the RX10 II.
Macro performance is good due to the short minimum focus distance, but those who require extreme macro may still prefer dedicated macro lenses or accessories.
The super slow-motion feature is unique in this class and can help capture stunning underwater behavior, but it demands careful lighting and stability to get usable results.
Battery life is moderate, and users should consider spares for extended use. Also, operating the small control buttons underwater can be challenging depending on the housing design.
The RX100 IV’s image quality approaches that of larger cameras in good light, but it may show more noise at very high ISO settings compared to full-frame sensors.
Detailed Specifications and Features of the Sony RX10 II
The Sony RX10 II is designed for versatility, with a larger zoom lens range equivalent to 24-200mm at a constant f/2.8 aperture. This makes it ideal for underwater photographers who want flexibility to shoot wide scenes and distant subjects without changing lenses.
It's 20.2-megapixel 1.0-type Exmor RS CMOS sensor with DRAM chip allows for fast image processing, supporting burst shooting at 14 frames per second and 4K video recording.
The constant aperture lens ensures consistent exposure and depth of field throughout the zoom range, which is especially useful for video.
Like the RX100 IV, it offers super slow-motion video capture and built-in Wi-Fi with NFC for connectivity.
The camera body is larger and more rugged than the RX100 IV, making it easier to handle underwater, especially with gloves. The ergonomics support longer shooting sessions and a better grip in wet conditions.
Strengths and Considerations of the Sony RX10 II for Underwater Photography
The RX10 II’s powerful zoom range and fast lens give it an advantage for divers who want an all-in-one solution for a variety of subjects without changing lenses. It excels at topside shooting, such as capturing marine life at the surface or wildlife on boats.
Underwater, the lens and sensor combination delivers excellent image quality, with good low-light performance thanks to the constant f/2.8 aperture.
The larger size of the camera makes it easier to control and steady during dives, which can help reduce image blur.
The 4K video and super slow-motion features offer creative options for underwater filmmakers.
Battery life is typically better than smaller compacts, allowing for longer sessions without swapping batteries.
The RX10 II is bulkier and heavier than the RX100 IV, which may be a consideration for travel and packing.
Practical Underwater Photography Considerations for All Three Cameras
When choosing between these cameras for underwater use, several practical factors come into play beyond specs:
Housings: Each camera requires a specific underwater housing to be used underwater safely. Housings vary in price, size, and feature support. The a7R II housings tend to be larger and more expensive due to the camera’s full-frame size and complexity. Compact housings are available for the RX100 IV and RX10 II, often with integrated ports for wide-angle or macro lenses.
Lighting: Underwater photography benefits greatly from external strobes to compensate for light loss and color shift at depth. All three cameras support external lighting systems, but the choice of housing and rig will determine how easily strobes can be mounted.
Portability: The RX100 IV offers the highest portability, suitable for travelers and divers who want a lightweight setup. The RX10 II balances zoom versatility and portability, while the a7R II is better suited for photographers prioritizing image quality and professional video.
Control: The a7R II offers the most manual control and customization options, appealing to experienced photographers. The RX100 IV and RX10 II offer intuitive controls but may be more limited in advanced settings.
Cost: Price points vary widely, with the a7R II being the most expensive camera body, followed by the RX10 II and RX100 IV. Housing and accessories also add to the overall investment.
Underwater Video Capabilities of the Sony a7R II, RX100 IV, and RX10 II
Video shooting is increasingly important for underwater photographers who want to capture dynamic marine life behavior and environments. All three cameras provide advanced video features suited for high-quality underwater footage, though each model approaches this slightly differently.
The Sony a7R II excels with internal 4K recording at 30 and 24 frames per second using the XAVC S codec. It records full pixel readout without pixel binning, which results in sharp, detailed video with minimal moiré and aliasing. The inclusion of S-Log2 Gamma expands dynamic range, allowing for better control in post-production grading and color correction, essential for underwater scenes with complex lighting.
Its 5-axis stabilization also enhances handheld video, reducing motion blur caused by water movement or diver instability. The a7R II supports external microphones, further improving audio quality for underwater video when paired with compatible housings that allow mic connections.
The RX100 IV offers 4K internal recording with a high frame rate option, supporting detailed, smooth footage in a compact form factor. It's super slow-motion mode at up to 960 frames per second captures fast underwater movements in extraordinary detail, which can highlight behaviors rarely seen in real time.
Similarly, the RX10 II includes 4K video with internal recording and the same super slow-motion capabilities. Its longer zoom lens extends creative possibilities for video, allowing subjects to be captured from a distance without disturbing them.
Both compact cameras provide built-in Wi-Fi for quick file transfer, enabling underwater videographers to share clips rapidly or control the camera remotely when out of the water.
Tips for Maximizing Underwater Photography with These Sony Cameras
Achieving excellent underwater images and videos with these advanced cameras requires attention to technique and gear setup.
Lighting is crucial. Even the best sensor cannot compensate for lost light and color shifts that occur underwater. Using powerful, balanced strobes close to the subject will restore colors and reduce backscatter. Position strobes to create dimension and avoid harsh shadows.
Manual control over exposure and focus settings helps overcome underwater challenges. Experimenting with aperture and ISO will help find the best balance between sharpness and noise. Using the camera’s focus peaking or magnification features assists with precise focusing on small or moving subjects.
Stabilizing the camera is key, especially with the high resolution of the a7R II and the slow-motion modes of the RX100 IV and RX10 II. Using grips, trays, or arm systems in housing rigs can reduce shake.
Shoot in RAW format when possible, particularly with the a7R II, to maximize post-processing flexibility for color correction and noise reduction.
Practice and familiarity with each camera’s menu and controls streamline operation underwater, where time and visibility may be limited.
Comparing the Three Cameras for Different Underwater Use Cases
For photographers prioritizing image quality and professional-level video, the Sony a7R II is the top choice. Its full-frame sensor, high resolution, and advanced autofocus make it ideal for serious underwater photographers and videographers who demand the best detail and dynamic range.
The Sony RX100 IV is perfect for divers seeking a pocketable, versatile camera with excellent image quality and advanced video features. It’s well-suited for casual to enthusiast underwater photographers who want an easy-to-use camera without carrying heavy gear.
The Sony RX10 II offers a balance between portability and zoom versatility, appealing to those who want an all-in-one camera capable of capturing a wide range of subjects from macro to distant scenes, including topside wildlife or landscape shots.
Conclusion
Sony’s a7R II, RX100 IV, and RX10 II cameras each bring unique strengths to underwater photography and videography. The a7R II stands out with its exceptional resolution, dynamic range, and professional video capabilities, making it the preferred choice for dedicated shooters who want the highest image quality and flexibility. Meanwhile, the RX100 IV delivers remarkable performance in a compact package, offering portability and cutting-edge sensor technology ideal for divers on the go. The RX10 II’s extended zoom and rugged design provide a versatile solution for underwater photographers seeking flexibility without the need for interchangeable lenses.
Selecting the right camera depends on your specific underwater photography goals, budget, and willingness to manage equipment size and complexity. Regardless of choice, pairing these cameras with quality housings and lighting will unlock their full potential beneath the waves.
As underwater housings become available and in-water testing progresses, further insights will help refine usage recommendations and tips to get the most out of these impressive Sony models.