Canon G7X Mark III Review

Canon G7X Mark III: Initial Thoughts

The Canon G7X Mark III is an excellent, first-rate camera in a small body. It is an upgrade from the famous G7X Mark II, the Mark III incorporates a similar sensor and the same lens, but there have been significant improvements to the camera’s processing capabilities. Specifically, the camera now features a “stacked” sensor and a DIGIC 8 image processor. 
Updates in the G7X Mark III's hardware resulted in an improved burst shooting rate (now 20 fps), 4K video capability (no crop!), improved image buffer (now 70 shot RAW), and slow-motion video in 1080p. Although the image quality will remains the same, these improvements will give underwater photographers new tools underwater. 
The G7X Mark II led the compact camera market for the last two years. But a lot of has happened in two years, especially when you look at Canon’s competitors – the Sony RX 100 V/VA and the Sony RX100 VI and even the Olympus TG-6. That being said, the G7X Mark III is definitely the camera to bring Canon back to the future. We can’t wait to take this camera underwater and put it to the test.
U.S. MSRP Canon G7X Mark III: $750
Canon G7X Mark III Review

Canon G7X III compared with G7X II

The upgrades on the Canon G7X Mark III from the G7X Mark II will be welcomed mostly by video-shooters and vloggers. There were a few improvements made to the camera that are exciting for underwater photography – most notably when it comes to 4K video, slow motion video (@1080p) , burst shooting, buffer, and the new stacked CMOS sensor. 

Canon G7X Mark III Specifications

Key Upgrades from the G7X Mark II

• 4K video @ 30fps and 1080p @ 120 fps
• Built-in Bluetooth and WiFi
• Ability to shoot panoramas
• External microphone jack
• 20 fps burst mode (upgraded from 8fps)
• 70 shot RAW buffer (upgraded from 21 shots)
• Ultra-fast electronic shutter for shooting wide open aperture in daylight – 1/25,600s
• Slow motion video (120 fps in 1080p)
• Supports vertical video shooting (not for live-streaming)
• Supports live streaming videos to YouTube
• Cheaper than the Canon G7X Mark II on release date
• New stacked CMOS sensor
• DIGIC 8 image processor

Additional Key Canon G7X Mark III specs

• 20.1 megapixel 1.0” stacked CMOS sensor
• DIGIC 8 image processor
• 4.2x optical zoom lens (24-100m f/1.8-2.8) with optical image stabilization
• 3.0 inch touch panel LCD screen with tilt option of 180 degrees for selfies and vloggers
• Compatible with USB charge/power supply
• Contrast-detection autofocus (no dual pixel autofocus)
• Clean HDMI output
• Native ISO: 125 – 12,800
• Size: 4.1” X 2.4 “ X 1.6 “
• Weight: 11.3 oz (319 g)

Improved Video Capability

The G7X Mark III’s most enticing update by far is its new and improved video capability. 4K video capability in most cameras is standard here in 2019. Canon brought the G7X III to the present with 4K capability at 30 fps. It’s a relief that there is no 4K crop factor, so the full potential of the sensor is utilized resulting in crisp video details. Slow motion video capability (120 fps) is available at 1080p. This will be great for any underwater photographer looking to capture quick moments underwater – like schools of fish, dolphins, sea lions, sharks, etc.
There have also been some exciting updates made for topside photographers as well. The G7X Mark III now supports video live streaming on YouTube as well as vertical video shooting. 

Improved Photo Capability

There are a number of improvements to the G7X Mark III’s photography processing; all of these improvements are a result of the new 1-inch stacked CMOS sensor and the DIGIC 8 processor. Although the new sensor seems similar to the sensor on the G7X Mark II, the “stacked” desing means that it has one layer for collecting data and one layer for processing. This results in the camera having more ability to process images. The G7X Mark III’s burst shooting capability has been improved from 8 fps to a whopping 20 fps - that's better than many full-frame systems! The RAW buffer has also been improved to 70 shots from 21. This is very exciting for underwater photographers who want something small that can capture fast animals underwater. So what exactly does all of this translate to? Well, you can shoot RAW at 20fps for just over three second continuously before the camera needs to take a break to process. That’s perfect for getting dive bombed by a cormorant or passed by a sea lion. Unfortunately, burst shooting is only 8.3 fps when shooting with continuous AF, not that 8 fps is slow… 
Side note: The G7X Mark III has also been updated to shoot Panoramas! Not the most useful feature for underwater photographers, but very cool nonetheless. Check out our guide to shooting underwater panoramas. 

Canon G7X Mark III Key Features

Body and Build

At 4.1” X 2.4 “ X 1.6 “ and weighing in at less than 1lb, the Canon G7X Mark III is a very compact camera. It’s hard to find many cameras smaller and more compact to bring underwater. For many divers, the size of the Mark II is one of its main selling points, and this will likely be the same for the G7X Mark III. 
The G7X Mark III also features a 3 inch touch screen LCD that can be flipped up by 180 degrees for selfies. Canon is trying to appeal to the vlogger market with an external microphone jack and built-in WiFi/Bluetooth. Moreover, G7X Mark III's 3 inch touch screen LCD can be flipped up 180 degrees for selfies


We look forward to taking the Canon G7X Mark III underwater to test its AF capability once housings start coming out for the camera. As of yet, it sounds the Mark III shares a contrast-detect autofocus system with the Mark II. Although it’s not terrible, some people had high hopes for Canon’s famous dual pixel autofocus. We’ll just have to wait for the next iteration! 

Sensor and Image Quality

There has been an upgrade in the sensor of the G7X Mark III, but not a huge one. Although a “stacked” CMOS sensor improves image processing, it won’t necessarily improve image quality. We expect the G7X Mark III’s image quality to be similar to the Mark II. That being said, the image quality is still excellent – 20.1 MP is impressive for any compact sensor. Check out the G7X Mark II photos below to see for your self (at least until we take the G7X Mark III underwater).
The lens on the Mark III appears to be the same as the Mark II, which means it is versatile for both wide angle and macro underwater photography – especially with wet lenses. 

G7X Mark III for Underwater Photography

The Canon G7X Mark III will be one of the best choices for underwater photo and video in the compact camera market. The G7X Mark III has made the G7X line modern with 4K video recording, quick burst modes, and large buffers. 
Ultimately, underwater photographers will benefit with upgrades in processing and have newfound ability to capture quick subjects, whether its slow motion video or burst shooting. We expect underwater controls to be similar to the Mark II with aperture and shutter speed at your fingertips and ISO one tap away. Underwater macro and underwater wide angle shooting is bound to be a joy with the G7X Mark III’s zoom lens, especially with accessories like wet diopters and wide-angle wet lenses. 

Canon G7X Mark III Underwater Lenses

Wide-Angle Wet Lenses

A wide-angle wet lens increases your field of view, which means that you get more background behind your subject and must be closer to it.This means that you will often get less water between the camera and your subject than if you did have a wide anlge lens. Less water means a clearer subject, as well as better lighting from a video light, photo light or strobe....and ultimately better colors. A wider angle also allows for more dramatic shots, especially with large subjects like oil rigs, kelp forests, large animals, reefscapes and wrecks.
We recommend using the UWL-04 fisheye lens, with its 165 degree wide angle of view will allow you to create stunning wide-angle shots. Other great options to consider are the Kraken KRL-01 and KRL-02 wet wide angle lenses, which provide 145 and 150 degree angles of view, respectively.

Macro Wet Lenses

Although the Canon G7X Mark III has a macro mode, the best option for underwater macro photography is to use a diopter. The Bluewater +7 macro lens gives very good results. We recommend stacking 2 of these lenses for supermacro.

Canon G7X Mark III Underwater Housings

Because the G7X Mark III shares dimensions with the Mark II, it’s quite possible that the Mark III will be compatible with housings for the Mark II. That being said, we won’t be able tell if this is true until manufacturers come out with the first G7X Mark III housings. We expect underwater housings from Fantasea, Ikelite, Nauticam, and Isotta. 

Be sure to keep checking these pages for major underwater housing brands for updates on the G7X Mark III's housing options:

Ikelite Canon G7X Mark III Underwater Housing


Nauticam Canon G7X Mark III Underwater Housing


Fantasea Canon G7X Mark III Underwater Housing



Sample Images from the G7X Mark II

(until housings for the G7X Mark III are released)

As the G7X Mark II and G7X Mark III have basically the same sensor (with minor differences), underwater photos will be similar. We’ll update this section once we take the G7X Mark III underwater. See our Canon G7X Mark II review for more! Thanks for reading our Canon G7X Mark III review and stay tuned for updates soon.








The Canon G7X Mark III is the long-awaited successor to the highly-successful G7X Mark II. While it faces tough competition from the Sony RX100 VI and Sony RX100 V/VA, it holds its ground with the addition of 4K video, 20fps burst, and a 70 shot RAW buffer.
The new 1”  20 MP “stacked” CMOS sensor is bound to deliver great image quality with improved processing ability. What more could you ask for in such a small, easy-to-use underwater package?
Canon G7X Mark III initial thoughts and review for underwater use with recommended lenses and settings.