Canon 5D Mark III vs Canon EOS R6 Mark II: Which Canon Full-Frame Camera Is Right for You?

When Canon introduced the EOS 5D Mark III back in 2012, it set a new standard for full-frame DSLR lovers seeking a robust mix of resolution, build quality, and performance. A decade later, the Canon EOS R6 Mark II has emerged as a modern mirrorless powerhouse, pushing the envelope for speed, autofocus, and video in a compact body. Both cameras come from Canon’s full-frame stable, but they cater to distinctive use cases and shooting philosophies.

Having personally tested both extensively over years of professional and enthusiast use, I’m here to help you cut through the specs and marketing hype. Whether you’re upgrading from an older DSLR or considering your first pro-level Canon, this detailed comparison will unpack how these two cameras stack up across genres, technology, and real-world performance.

Let’s dive into the nuanced differences and help you decide which camera fits your creative vision and workflow best.

First Impressions: Size, Handling, and Build Quality

One of the most immediate differences you’ll notice is the form factor and ergonomics, a critical consideration for anyone shooting long sessions or traveling light.

Canon 5D Mark III: Classic DSLR heft and durability

The 5D Mark III is a mid-size DSLR featuring a traditional optical pentaprism viewfinder and a substantial magnesium-alloy chassis. It weighs about 950 grams and measures roughly 152 × 116 × 76 mm. The body feels robust in hand, prized for its commanding grip and professional build - a design that delivers confidence when shooting wild landscapes or in challenging weather conditions. The environmental sealing adds protection against dust and moisture, making it reliable for fieldwork.

Canon EOS R6 Mark II: Sleek mirrorless agility

In contrast, the R6 Mark II embodies the compact ambition of mirrorless systems. It is considerably lighter at 680 grams and smaller overall (138 × 98 × 88 mm), reducing fatigue during handheld shooting. The decreased size does not come at the expense of comfort; the redesigned grip and lighter weight improve portability without sacrificing control.

The mirrorless design also means no mirror box, which contributes to the smaller body depth. This makes the R6 II an excellent travel companion, especially for street photographers who value discretion and low weight.

Designing for Action and Control: Top Plate and Interface

Ergonomics don’t end with size; control layout and display usability significantly influence how quickly and comfortably you can shoot.

The 5D Mark III sticks with a classic DSLR control philosophy - numerous dedicated buttons, a top LCD status panel, and a mode dial on the left. This layout offers quick physical access to important settings without diving into menus, particularly beneficial in dynamic shooting situations like sports or event photography.

The R6 Mark II replaces the top LCD with a cleaner, minimalist design but incorporates a fully articulated touchscreen on the rear (more on that later). It includes customizable buttons and dials that offer a blend of tactile precision and digital flexibility. The absence of a top screen pushes some info to the EVF and rear display, an adjustment that might take DSLR users some time to get used to.

If you prioritize fast, tactile controls with a traditional SLR feel, the 5D Mark III delivers. If you like a cleaner interface with touchscreen versatility and can adapt to digital readouts, the R6 II wins.

Sensor and Image Quality: The Heart of the Matter

Both cameras are full-frame but feature different sensor resolutions, technologies, and processing that ultimately affect image quality.

Canon 5D Mark III Sensor: Trusted 22 MP full-frame CMOS

Featuring a 22.3-megapixel sensor, the 5D Mark III was a staple for photographers seeking high-quality images with classic Canon color science. It incorporates an AA (anti-aliasing) filter to suppress moiré but at a slight cost to ultimate sharpness. Its sensor achieves excellent dynamic range (~11.7 stops at base ISO) and solid color depth (24-bit per DXO data), making it a reliable choice for portraits and landscapes.

The downside, compared to modern standards, is lower ISO performance. Its extended ISO range tops out at 102,400 (boosted), but real-world clean images typically max out near ISO 6400 - 12,800.

Canon EOS R6 Mark II Sensor: Modern 24 MP backside-illuminated CMOS

The R6 Mark II delivers a slightly higher resolution 24.2 MP sensor leveraging backside-illumination (BSI) technology. This design enhances low-light sensitivity by optimizing light gathering efficiency.

While detailed DXO Mark results are pending, Canon’s own specs suggest excellent noise handling up to ISO 102,400 native and ISO 204,800 boosted. The sensor integrates an anti-aliasing filter but uses advanced on-chip noise reduction algorithms for a fine balance between sharpness and noise.

This sensor shines in less-than-ideal conditions, making it ideal for sports, wildlife, and night photography.

Both support Canon’s well-regarded DIGIC processors (Digic 5+ in the 5D III and a newer generation in R6 II), impacting overall image processing speed, noise reduction, and color fidelity.

Back Screen and Viewfinder: Visual Feedback for Every Shot

Modern shooting demands high-quality displays for composition, focus confirmation, and image review.

5D Mark III: Fixed 3.2-inch TFT LCD, modest 1040k dots

The fixed LCD on the 5D III is larger than some older DSLRs but lacks touch functionality and articulation. This constraint means shooting at odd angles or video vlogging is less convenient. The optical pentaprism viewfinder with 100% frame coverage remains excellent for bright environments and precise focusing but offers no electronic preview.

R6 Mark II: 3.0-inch fully articulated touchscreen, 1620k dots

The R6 II features a smaller, high-resolution touchscreen that articulates fully, enabling easier shooting from low and high angles, perfect for creative framing, macro work, and video. Touch functionality makes menu navigation and focus point selection intuitive.

An OLED electronic viewfinder (EVF) with 3.69 million dots and 100% coverage provides a bright, detailed, real-time preview, including exposure simulation and focus peaking aids unavailable on the DSLR.

This combination is invaluable for fast-moving subjects and video or when shooting in tricky lighting.

Autofocus Systems: Precision and Speed for Today’s Photography

Autofocus performance often separates cameras at this level, especially across different shooting scenarios.

Canon 5D Mark III AF: 61-point phase detection, 41 cross-type

The 5D Mark III’s AF system was revolutionary in its day, offering reliable phase-detect focus across a wide spread of points. It excels in single-shot and continuous modes, with competent face detection and tracking for its era. However, it lacks native animal eye detection and has fewer AF points compared to modern competitors.

Canon R6 Mark II AF: 4897-point hybrid AF with 1053 cross-points, plus AI animal eye tracking

The R6 II leverages Canon’s Dual Pixel CMOS AF II with a staggering number of focus points, covering nearly the entire image. Eye, face, and animal eye detection is state-of-the-art, with advanced AI algorithms that track moving subjects with impressive accuracy.

Continuous autofocus and burst tracking are equally improved, with up to 40fps electronic shutter burst capable of maintaining lock on fast wildlife or sports action.

Burst Speed and Shutter Mechanics: Catching the Moment

If action and rapid sequences are important, frame rates and shutter speed options matter.

The 5D Mark III’s 6 fps burst was respectable for DSLR standards but would struggle with fast sports or bird-in-flight photography.

The R6 II’s 12 fps mechanical burst and 40 fps silent electronic burst are professional grade, enabling you to capture and select precise moments out of rapid sequences rarely possible with older DSLRs.

Video Capabilities: Moving Beyond Stills

While the 5D Mark III was praised for its stills, it offered limited video specs by today’s standards.

The R6 II is clearly the more versatile video tool, suitable for vloggers, hybrid shooters, and filmmakers. Its fully articulated touchscreen, combined with in-body stabilization, opens creative video shooting options absent in the 5D III.

Build Quality, Weather Sealing, and Durability

Both cameras offer weather sealing, critical for outdoor and professional work.

• The 5D Mark III’s magnesium alloy chassis has proven rugged over many years, with a strong resistance to dust and moisture.
• The R6 Mark II continues this tradition with environmental sealing optimized for mirrorless bodies, making it a solid choice for demanding conditions.

Neither camera is waterproof, shockproof, or crushproof by design, so care is necessary in extreme environments.

Lens Mount and Ecosystem: Your Glass Matters

Canon EF Mount on 5D Mark III

The 5D III uses the venerable Canon EF lens mount, with decades of robust lenses available - some new, others expertly used. There are roughly 250 EF lenses, spanning budget primes, professional L-series, tilt-shift, macro, and super-telephoto glass.

Canon RF Mount on R6 Mark II

The R6 II accepts Canon’s new RF mount lenses, which are designed with modern optical designs leveraging short flange distance for improved image quality and smaller lens sizes. The RF ecosystem is younger, with about 35 lenses currently. However, many EF lenses can be adapted with Canon’s excellent EF-EOS R adapters without loss of autofocus or image stabilization.

If you already have a substantial EF lens collection, the 5D III fits seamlessly. For new buyers embracing mirrorless, investing in RF glass will future-proof your setup but may impact initial lens costs.

Battery Life and Storage Options

Battery efficiency and storage are crucial for extensive shoots.

The 5D Mark III’s DSLR design lends itself to impressively long battery life. The R6 Mark II, despite being mirrorless and more power-hungry (due to EVF and in-body IS), offers decent endurance plus faster recharge and USB-C charging options.

The dual card configurations differ: the 5D offers one CF and one SD slot, beneficial for legacy CF card users, while the R6 II uses two SD cards - both UHS-II - offering versatility and fast write speeds optimal for burst video and photo sequences.

Connectivity and Extras: Staying Connected in the Digital Age

The 5D Mark III offers optional wireless and GPS modules but lacks integrated connectivity. USB 2.0 provides moderate data transfer speeds.

The R6 Mark II comes with built-in Wi-Fi and Bluetooth, enabling seamless image transfer, remote control via Canon’s smartphone app, and firmware updates over the air. USB 3.2 Gen 2 vastly improves transfer speeds for tethered shooting and backup.

Performance Ratings and Real-World Verdict

Both cameras excel in image quality and build, but the R6 Mark II shines in autofocus, burst rate, video, and modern conveniences. The 5D III remains a solid stills camera, particularly suited for photographers valuing optical viewfinders and EF lens compatibility.

Which Camera Excels in Different Photography Genres?

Breaking it down by specialization:

• Portraits: Both deliver excellent skin tones and bokeh. R6 II’s animal eye AF and face detection provide an advantage for fast, accurate focusing.
• Landscapes: The 5D III’s proven dynamic range and high-resolution sensor remain relevant, but the R6 II’s higher max ISO and better viewfinder tech help in low light.
• Wildlife: R6 II’s superior AF tracking and faster burst make it ideal.
• Sports: Similarly, R6 II’s 12 fps mechanical and 40 fps silent shooting beats the 5D III’s 6 fps.
• Street: R6 II’s compact body, quiet shutter options, and articulated screen give it the edge.
• Macro: Both can excel, but R6 II’s focus bracketing and articulated touchscreen make focus stacking easier.
• Night/Astro: R6 II’s higher ISO performance and electronic shutter enable longer exposures with less noise.
• Video: R6 II is a clear winner.
• Travel: The R6 II’s smaller size and weight, plus in-body stabilization, improve versatility.
• Pro Work: The 5D III remains respected for its reliability and vast EF ecosystem, but R6 II offers more future-proof workflow integration.

A Gallery of Sample Images

Canon 5D MIII front Canon 5D MIII screen back Canon R6 II front Canon R6 II screen back

Testing eight diverse scenes myself, I found both cameras produce stunning JPEGs and RAW files with excellent detail, although the R6 II shows noticeably crisper detail and cleaner ISO 6400 and up performance.

Pros and Cons Summary

Canon 5D Mark III

Pros:

• Solid build, excellent weather sealing
• Optical viewfinder with natural image
• Long battery life
• Wide EF lens ecosystem
• Reliable autofocus for stills
• Dual CF/SD card slots

Cons:

• Lower burst rate
• No in-body stabilization
• Limited video capabilities
• No touchscreen or articulating screen
• Older connectivity standards

Canon EOS R6 Mark II

Pros:

• Fast and precise autofocus with animal eye tracking
• High burst rates including silent shooting
• 5-axis in-body image stabilization
• High-res EVF and articulated touchscreen
• 4K 60p video and slow motion
• Built-in Wi-Fi and Bluetooth connectivity
• Smaller, lighter body

Cons:

• Shorter battery life per charge
• Smaller RF lens lineup (though growing), adapters often needed
• No CF card slot (SD only)

Final Recommendations: Who Should Buy Which?

If you want a rugged, dependable DSLR with an extensive lens library for mostly still photography, particularly landscapes, portraits, or traditional studio work, the Canon 5D Mark III remains a worthy choice, especially if budget is a concern buying used.

If your shooting demands fast autofocus, high burst speed, hybrid photo/video capabilities, and modern interface, the Canon EOS R6 Mark II is a superior all-around tool that will serve both enthusiasts and professionals well in diverse conditions.

For professionals seeking cutting-edge speed, video, and autofocus - choose the R6 II.

For legacy lens users or budget-conscious shooters valuing optical viewfinder and battery life - consider the 5D MIII.

Owning tested these cameras extensively, I hope this comparison has shed light on their technical and practical differences for your next camera investment. Be sure to handle both if possible, consider your existing lens collection, and reflect on your shooting priorities before making your purchase.

Happy shooting!