The Canon 5D Mark IV is the long-awaited upgrade to the 5D Mark III. It aims to be an all-around powerhouse with many new features for both stills and video. This review focuses on the video capabilities of the 5D Mark IV. The ability to shoot 4K video at 24 and 30 frames per second, 1080p at 60fps, and 720p at 120fps is a welcome addition to the 5D lineup.
The Dual Pixel servo autofocus in video mode is a game changer for DSLRs, marking the first time this feature appears in the 5D family and only the second in Canon’s lineup. Having servo autofocus with the ability to track moving subjects is a major upgrade from the 5D Mark III. The 5D Mark IV also records video in 4:2:2 color space, allowing for greater latitude in color correction compared to its predecessor. Although the ISO range did not increase significantly, the quality at higher ISOs has noticeably improved. Another new feature is HDR video recording in 1080p, which reduces highlight and shadow clipping and achieves a higher dynamic range while filming. Overall, these video enhancements combined with the 30-megapixel sensor for stills make this a substantial upgrade over the 5D Mark III.
Video Autofocus
The most important and significant upgrade in the 5D Mark IV is the Dual Pixel Autofocus system, which allows continuous autofocus while recording video. This makes the 5D Mark IV the first full-frame DSLR to offer continual focus during video capture. The movie servo autofocus options include Face Detection with tracking, FlexiZone Multi, and FlexiZone Single modes. Even when wearing a dive mask underwater, face detection works effectively, although it does not track animals. For underwater shooting, face detection or FlexiZone Multi are recommended because the camera focuses on the dominant subject in the frame and continually tracks it. FlexiZone Single focuses only on the specific area inside the white square on the screen. The autofocus performance is smooth and fast, and the focusing speed can be adjusted in FlexiZone mode, offering creative control over the focus transition. This allows the shooter to let the camera roll while the autofocus tracks moving subjects seamlessly.
This continuous autofocus system is far superior to manual focusing, which requires constant adjustment of the lens focal distance for different subjects. However, there are situations where manual focus is preferable. For example, in scenes with multiple subjects moving erratically, autofocus can struggle to decide which subject to focus on. While diving at a sea lion rookery, multiple pups moving in and out of the frame made autofocus inconsistent. In hindsight, turning autofocus off and manually setting the focal length was a better choice. Overall, the Dual Pixel autofocus is an exciting advancement for DSLR video, enabling dynamic camera movements that were previously difficult to achieve.
Video Image Quality and Memory Cards
The 5D Mark IV’s 4K video capability elevates image quality significantly beyond what the 5D Mark III could produce at 1080p. The detail, color fidelity, and dynamic range in 4K footage are outstanding. The camera records 4K video using the Motion JPEG codec at 500 Mbps, delivering sharp, vibrant images previously unattainable on this line of cameras. However, this codec has pros and cons. The file sizes are large, requiring very fast and high-capacity CompactFlash (CF) memory cards. One minute of 4K footage can take up approximately 4GB of storage. The camera features both a CF and an SD card slot, but shooting 4K video to the SD card is not recommended. The SD slot supports only the slower UHS-I interface, which limits write speeds below what 4K recording demands.
Despite speculation about why Canon chose the Motion JPEG codec—given its large file sizes compared to competitors—the codec excels in image quality. The footage offers impressive latitude and sharpness, and users can even extract high-resolution 8.8-megapixel still frames directly from the 4K video.
Another advantage over the 5D Mark III is the improved latitude for color correction in post-production. The 5D Mark IV records in 4:2:2 color space, allowing greater flexibility to adjust exposure, highlights, shadows, and tones. For filmmakers who grade their footage, downloading the Cinestyle picture profile is recommended. This profile produces a flat image with increased detail in highlights and shadows, enabling more precise color grading than standard in-camera profiles. Additionally, the camera supports HDR video recording, although only at 1080p and 24 or 30fps. This HDR mode enhances detail in both shadows and highlights and is a valuable tool for underwater shooters needing greater dynamic range.
Format and Field of View
The 5D Mark IV’s 4K footage is recorded in a slightly wider Cinema 4K format of 4096x2160 pixels, which requires cropping the sides to fit the standard 16:9 aspect ratio. The camera takes a 1:1 pixel crop from the center of the sensor to create the 4K video frame, resulting in a 1.64x crop factor. This crop is a challenge for full-frame shooters expecting full lens coverage. For example, a 16mm lens will provide a field of view similar to 26.2mm in video mode. This crop factor can be an advantage or disadvantage depending on the shooting style. Macro shooters benefit from the crop since it increases magnification while maintaining a shallow depth of field. Wide-angle shooters must anticipate the crop when framing video shots, especially if switching between stills and video during the same dive. Zoom lenses like Canon’s 8-15mm fisheye are good options for ultra-wide shots, while the 16-35mm lens works for medium to wide shots. Despite this, even at 16mm, the effective field of view is about 26mm. Users will need to adjust framing strategies between still photography and 4K video, but the improved image quality justifies the extra effort.
One of the key considerations for underwater videographers is the camera’s performance at various ISO settings, especially since underwater conditions often require shooting in low light or murky environments. The Canon 5D Mark IV offers an ISO range from 100 to 32,000 in standard mode, with expansion available from 50 to 102,400. This is a slight increase over the 5D Mark III, which maxed out at ISO 25,600 (expandable to 102,400). However, it is not just the range but the quality of the footage at higher ISOs that has improved significantly.
Testing the 5D Mark IV at various ISO levels reveals notable advances in noise control and color fidelity. At ISO 1250, noise is minimal and almost unnoticeable in smooth color gradients, making it very usable for many underwater shooting conditions. Even at ISO 3200, noise remains relatively low and primarily visible only in shadow areas, maintaining excellent overall image quality. This means the camera can capture usable footage in a dim underwater environment, such as at dusk or in deeper water where light is scarce.
At ISO 6400, noise becomes more apparent but can be managed effectively with post-production noise reduction software. This is a substantial improvement over the Mark III, where footage at this ISO was often grainy and lacked detail. The ability to shoot at higher ISOs with better image quality expands the creative possibilities underwater, especially for those who do not wish to rely solely on artificial lighting or strobes.
ISO settings beyond 12,800 are generally not recommended for video, as noise becomes very intrusive and detail is lost. This limitation is consistent with many full-frame DSLRs but is balanced by the camera’s strong performance within its practical ISO range.
Dynamic Range and Highlight Recovery
Dynamic range, or the camera's ability to capture detail in both shadows and highlights simultaneously, is critical when filming underwater scenes with complex lighting—such as sun-dappled reefs or bright surface conditions contrasting with darker depths.
The 5D Mark IV shows a marked improvement in dynamic range compared to its predecessor. Where the 5D Mark III often suffered from highlight clipping in high-contrast scenes, the Mark IV reduces this clipping significantly, preserving more detail in bright areas. This is particularly important for underwater shooting where reflective surfaces, sunlight filtering through water, and bright white sand can easily blow out highlights.
Shadow detail is also better preserved, giving the footage a balanced exposure and richer tonal range. This improvement reduces the need for heavy corrections during post-processing, saving time and preserving image integrity.
The camera's ability to shoot HDR video in 1080p adds another layer of flexibility. HDR video mode combines multiple exposures to capture an extended dynamic range, allowing filmmakers to achieve well-balanced images even in scenes with extreme contrast. This feature is especially valuable underwater, where the balance between ambient light and shadow is often challenging to manage. Although HDR is limited to 1080p resolution and frame rates of 24 or 30 fps, it provides a practical option for shooters who prioritize dynamic range over resolution.
Color Science and Grading Potential
Color rendition is a vital component of video quality. Underwater environments often suffer from color loss and distortion due to water absorption and scattering of light, so cameras with strong color science and grading latitude provide a significant advantage.
The 5D Mark IV records video in 4:2:2 color space, which offers greater color information and finer gradations than the 4:2:0 format used in many previous models. This allows for more precise and extensive color grading in post-production without severe banding or color artifacts. The richer color data also enables underwater videographers to correct for the typical blue-green color cast underwater and bring out the true colors of marine life and coral reefs.
To maximize color grading potential, many filmmakers use Canon’s Cinestyle picture profile, which produces a flat, low-contrast image that preserves detail in both shadows and highlights. This profile gives editors greater latitude when adjusting contrast, saturation, and color balance. It also helps prevent clipping and posterization during color correction workflows.
The Canon 5D Mark IV’s improved color depth and dynamic range, combined with the ability to shoot in a flat picture profile, make it a highly versatile tool for underwater video professionals who want the freedom to craft their footage’s look in post-production.
Autofocus Performance in Challenging Conditions
While the Dual Pixel Autofocus system is generally fast and reliable, underwater environments pose unique challenges that can test its limits. Factors such as low light, particles in the water, and multiple moving subjects can cause the autofocus to hunt or hesitate.
The face detection mode performs admirably underwater when shooting people or divers, even when wearing masks. It consistently tracks the primary subject and maintains sharp focus, reducing the need for manual adjustments. This is a tremendous advantage for documentary-style shooting or capturing spontaneous moments without having to stop and refocus.
In wildlife or macro videography, where subjects are small, fast-moving, or partially obscured by floating debris, autofocus can occasionally struggle. For example, when filming a group of sea lions or a school of fish, the autofocus may “flip” between subjects or lose focus due to rapid changes in distance and movement patterns.
In such scenarios, manual focus remains the safer choice. Experienced shooters often pre-focus at a fixed distance or use focus peaking aids to ensure sharpness where needed. Despite these occasional limitations, the autofocus system’s ability to track moving subjects smoothly represents a major step forward from previous models and offers creative opportunities for capturing dynamic underwater footage.
Storage and Workflow Considerations
The Canon 5D Mark IV’s 4K video files are large due to the Motion JPEG codec and high bit rate of 500 Mbps. This means shooters must plan their storage carefully, using fast and high-capacity CompactFlash cards to handle the data stream without dropped frames or recording interruptions.
The camera’s dual card slots provide some flexibility. The primary slot uses CF cards capable of the necessary speeds, while the secondary slot accepts SD cards, which are slower and not recommended for 4K video. For underwater videographers, having fast, reliable media cards is critical, as reformatting or changing cards underwater is impractical.
File management is also important. One minute of 4K footage consumes roughly 4GB of storage, so long dives or extended shooting sessions require multiple high-capacity cards. Backup and offloading procedures should be established to safeguard footage, especially when working remotely or on location.
Post-production workflows benefit from the camera’s high image quality but require powerful hardware and sufficient storage capacity to handle large file sizes and the demands of color grading and noise reduction. Investing in a robust editing system with fast drives and a capable GPU will streamline editing of 4K underwater footage from the 5D Mark IV.
Lens Selection and Underwater Framing
Due to the 1.64x crop factor when shooting 4K video, lens choice greatly impacts framing underwater. Wide-angle lenses used for still photography may become less effective for video, with the field of view narrowed considerably.
Macro shooters benefit from the crop factor, which increases magnification and helps isolate small subjects against blurred backgrounds. This effect enhances the aesthetic quality of close-up footage.
Wide-angle shooters need to adjust expectations and plan accordingly. Lenses like the Canon 8-15mm fisheye offer some flexibility to achieve ultra-wide perspectives despite the crop. The Canon 16-35mm zoom remains useful for medium to wide shots, but will not achieve the same ultra-wide look as on stills.
The cropping also affects composition and movement. Videographers must consider how the cropped field of view changes subject placement and camera movement. Practicing with the crop factor in mind helps avoid surprises during shooting and editing.
The Canon 5D Mark IV’s video capabilities mark a significant leap forward, particularly in autofocus, image quality, dynamic range, and color fidelity. While certain limitations, such as the crop factor and codec choice, require adaptation, the camera delivers a powerful toolset for underwater videographers. The improved ISO performance, HDR video, and 4:2:2 color recording expand creative possibilities in challenging underwater environments.
Storage demands and workflow considerations highlight the importance of preparation and equipment selection. However, those willing to invest time in mastering the system will find the 5D Mark IV a versatile and capable camera for capturing stunning underwater video.
Advanced Video Features and Customization
The Canon 5D Mark IV offers a range of advanced video features and customization options that appeal to professional and enthusiast videographers alike. These features allow fine control over exposure, focus, and image rendering, making it a flexible tool for underwater filmmaking.
One notable feature is the ability to adjust the autofocus speed and sensitivity in FlexiZone modes. This lets the user control how quickly the autofocus responds to changes in the scene, which is valuable when shooting fast-moving subjects or aiming for smoother focus transitions. Such control enhances creative expression by allowing the shooter to decide whether focus shifts are abrupt or gradual.
The camera also supports clean HDMI output, which enables recording uncompressed video to an external recorder. This expands post-production flexibility by capturing footage with less compression and higher bit depth than internal recording. For underwater videographers using housings and external recorders, clean HDMI output means better image quality and longer recording times, limited only by the recorder’s capacity.
In addition, the 5D Mark IV features a headphone jack and microphone input for improved audio monitoring and recording. Clear, high-quality audio is essential in documentary and interview-style underwater videos. Being able to plug in professional microphones and monitor audio in real-time ensures better sound capture and reduces the risk of unusable audio tracks.
Ergonomics and Handling Underwater
Handling a DSLR underwater requires a combination of camera ergonomics and housing design. The 5D Mark IV, while designed primarily as a terrestrial camera, performs admirably when paired with quality underwater housings.
The camera’s body is robust and weather-sealed, offering resistance against dust and moisture. This helps protect the camera inside the housing from humidity and condensation, common issues in underwater environments.
The layout of controls is logical and accessible, allowing quick adjustments to settings such as ISO, shutter speed, aperture, and autofocus modes. When mounted in a housing, many essential controls can be reached via external buttons and dials, reducing the need to open the housing during a dive.
However, the size and weight of the 5D Mark IV and its housings can be challenging during long dives or in tight spaces. Buoyancy adjustments are critical to balance the rig underwater, and divers often use additional weights or buoyancy aids to maintain neutral buoyancy.
The camera’s screen is a useful tool for composition and reviewing footage, but its visibility can be limited underwater depending on lighting and reflections on the housing port. Many underwater videographers rely on external monitors or viewfinders integrated into housings to improve visibility and framing accuracy.
Battery Life and Power Management
Battery life is a practical concern for extended underwater shoots. The Canon 5D Mark IV uses the LP-E6N battery, which offers respectable endurance for still photography but can be taxed more heavily during video recording, especially in 4K mode.
Recording 4K video consumes more power due to processor demands and continuous sensor operation. In typical use, the battery lasts between 1 to 1.5 hours of continuous video recording. For longer dives or shoots, carrying multiple fully charged spare batteries is essential.
Some underwater housings support external battery packs or have space for larger capacity batteries, which can extend shooting time significantly. Managing battery power carefully and monitoring remaining charge during dives ensures no footage is lost due to unexpected shutdowns.
Turning off non-essential functions like Wi-Fi, GPS, and image stabilization (if not needed) can also help conserve battery life.
Comparison with Competitors and Previous Models
Comparing the Canon 5D Mark IV to its predecessor, the 5D Mark III, and competing cameras highlights its strengths and limitations in underwater video.
The Mark IV’s 4K video capability, Dual Pixel autofocus, and 4:2:2 color recording give it a clear advantage over the Mark III, which is limited to 1080p video and lacks continuous autofocus in video mode. The image quality improvements alone justify the upgrade for videographers looking for higher resolution and better post-production flexibility.
However, some competitors offer more modern codecs (such as H.264 or H.265) that provide smaller file sizes and longer recording times. The Motion JPEG codec in the Mark IV, while excellent in image quality, creates large files that require fast storage and can limit recording duration.
Other cameras also offer better native dynamic range or higher ISO capabilities, but the Canon system’s color science and lens ecosystem remain major draws for underwater shooters.
When compared to mirrorless cameras, the 5D Mark IV is larger and heavier but may provide better battery life and durability in certain housings. Mirrorless systems often have better electronic viewfinders and silent shooting modes, but Canon’s Dual Pixel autofocus remains competitive.
Practical Tips for Underwater Video Shooting with the 5D Mark IV
To maximize the Canon 5D Mark IV’s potential underwater, several practical tips can enhance the shooting experience and final results.
First, pre-dive preparation is critical. Check and format memory cards, charge batteries, and ensure all camera settings are dialed in before entering the water. Familiarity with housing controls saves valuable dive time.
Second, use manual white balance or custom presets to compensate for the blue-green color cast underwater. Auto white balance can struggle in changing lighting conditions, so manually adjusting it helps maintain consistent color.
Third, take advantage of the camera’s HDR video mode for high-contrast scenes, but keep in mind the resolution limitation to 1080p. For projects requiring 4K, carefully manage exposure to avoid clipping.
Fourth, practice focusing techniques. While autofocus works well for many subjects, manual focus may be better for unpredictable or cluttered scenes. Use focus peaking or magnification features in the camera to assist.
Fifth, use fast lenses with wide apertures to capture more light and create pleasing background blur. Prime lenses like the Canon 35mm f/1.4 or 50mm f/1.8 are good options, as are fast zooms like the 16-35mm f/2.8.
Finally, post-processing is where the 5D Mark IV’s footage truly shines. Use color grading tools to correct white balance, enhance contrast, and reduce noise. Take advantage of the 4:2:2 color data and high bit rate for fine control.
Limitations and Areas for Improvement
Despite its many strengths, the Canon 5D Mark IV has limitations that users should be aware of.
The large file sizes from the Motion JPEG codec require significant storage capacity and computing power for editing. This can be a burden for shooters working in remote locations or with limited resources.
The 1.64x crop factor in 4K video narrows the field of view, which may frustrate wide-angle shooters used to full-frame coverage. This requires adapting lens choices and shooting styles.
While Dual Pixel autofocus is a leap forward, it can occasionally struggle with fast-moving or multiple subjects underwater. Manual focus remains essential for some scenarios.
The lack of 4K recording at higher frame rates (such as 60fps) limits slow-motion capabilities at high resolution. Although 720p can record at 120fps, the lower resolution may not meet all users’ needs.
Audio input and monitoring options are good, but could benefit from more professional-grade features for high-end productions.
Overall Impression and Suitability for Underwater Videography
The Canon 5D Mark IV represents a major advancement for underwater videographers who want to shoot high-quality video with a robust, versatile DSLR. It's 4K video, excellent color science, and Dual Pixel autofocus deliver footage that stands out in both clarity and creative potential.
The camera suits a wide range of underwater projects—from nature documentaries to professional commercial shoots and hobbyist explorations. Its strong lens ecosystem, reliable performance, and manageable workflow make it a solid choice for those committed to underwater filmmaking.
While it demands careful preparation and understanding of its crop factor and codec limitations, the benefits in image quality and autofocus innovation outweigh these challenges.
Conclusion:
In summary, the Canon 5D Mark IV is a powerful tool for underwater video. It combines high resolution, improved autofocus, and wide color gamut recording with Canon’s renowned image quality. Though it requires adaptation in lens choice and storage management, it opens new creative doors for underwater shooters.
Whether capturing the vivid life of coral reefs, dynamic marine animals, or cinematic underwater scenes, the 5D Mark IV delivers professional-level video that meets the demands of today’s underwater videography.