Olympus E-M5 vs Sony A7 III: A Hands-On Camera Comparison for Every Photographer’s Kit

When it comes to investing in a mirrorless camera, enthusiasts and pros alike face a dizzying array of options. Two cameras I often get asked to compare are the Olympus OM-D E-M5 and the Sony Alpha A7 III. Despite their generational gap - the E-M5 debuted in 2012, and the A7 III launched in 2018 - these two remain compelling in their own right, representing very different philosophies and camera lineages.

Having tested thousands of cameras over my 15+ years in photography gear reviews, I’ve put both bodies through their paces across multiple disciplines - from portraits to wildlife, landscapes to video. In this comparison, I’ll share insights from hands-on experience, technical breakdowns, and real-world usage, helping you decide which camera suits your style, budget, and workflow.

Let’s dive in.

Getting to Know the Bodies: Olympus E-M5 and Sony A7 III in Your Hands

On first glance, the Olympus E-M5 and Sony A7 III couldn’t be more different in build and size. The E-M5 is a compact, relatively lightweight micro four-thirds mirrorless designed for portability and agile shooting. At 122 x 89 x 43 mm and 425 grams, it nestles comfortably in smaller hands and fits easily into backpacks or even heavier coat pockets. Olympus designed the E-M5 with a classic SLR-style stance but kept the body compact enough for street shooters and travelers who don’t want to lug around DSLR-scale weight.

The Sony A7 III, by contrast, tips the scales at 650 grams and measures 127 x 96 x 74 mm - noticeably bigger and chunkier. This heft is due in large part to its full-frame sensor and beefier magnesium alloy body. It sits firm in the hand, offering plenty of grip room but demanding a bit more from your bag space. That said, its sturdy construction and weather sealing make it a workhorse for professionals who shoot outdoors or in challenging conditions.

Ergonomically, I found the A7 III sports a larger handgrip and more custom buttons, which is helpful when you want quick access to frequently toggled settings during fast-paced shooting. The Olympus, while smaller, impresses with its well-thought-out thumb rest and compact control layout, helping prevent fatigue during longer shoots.

Sensor Technology and Image Quality: Micro Four Thirds vs Full Frame

The heart of any camera’s imaging prowess lies in its sensor technology - and here lies the biggest technical distinction between these two.

The Olympus E-M5 features a 16MP Four Thirds CMOS sensor measuring 17.3 x 13 mm - considerably smaller than full-frame but making it one of the earlier micro four-thirds cameras to incorporate a backside-illuminated chip with the TruePic VI processor. The lens mount multiplier of 2.1x means a 25mm lens plays more like 50mm equivalent in full-frame terms. The smaller sensor area (around 225 mm²) impacts depth of field, bokeh, and low-light performance compared to larger sensors, but this comes with the benefit of smaller, lighter lenses and generally favorable DOF control for landscapes and street photography.

In contrast, the Sony A7 III brings serious firepower with its 24MP full-frame BSI-CMOS sensor measuring 35.8 x 23.8 mm, giving it over three times the sensor surface area (852 mm²) versus the Olympus. This boost translates into superior image quality, higher dynamic range (DxOmark rating of 14.7 stops vs 12.3 on the E-M5), and far better high ISO performance (native up to 51,200 ISO on the Sony, versus 25,600 ISO max on the Olympus).

In practical terms, this means the Sony will pull ahead in low-light, night photography, and in achieving shallow depth of field portraits with creamy bokeh.

Autofocus Systems and Speed: Accuracy Meets Tracking

Autofocus is an area where these cameras grow further apart.

The Olympus E-M5 employs a contrast-detection AF system with 35 focus points and face detection. At the time, it was considered fast for its class, providing reasonably reliable eye-detect autofocus for portraits. However, it lacks phase-detection AF, which affects tracking speed and accuracy during burst shooting or moving subjects.

The Sony A7 III, on the other hand, upgrades this with a hybrid autofocus system that combines 693 phase-detection points and 425 contrast-detection points across a wide AF coverage area. This system supports real-time Eye AF - including animal eye detection - and subject tracking that remains remarkably accurate even during fast sports or wildlife action. Burst shooting tops out at 10 fps with full AF tracking, which is a major asset for sports and wildlife shooters.

If you’re serious about tracking through erratic movements or low contrast scenes, the Sony’s AF system is clearly superior.

Handling and User Interface: Screens, Viewfinders, and Menus

The Olympus E-M5 features a 3-inch tilting OLED touchscreen with a modest 610k-dot resolution and a 0.58x electronic viewfinder offering 1440k-dot coverage at 100%. It’s responsive enough and offers touch AF, handy for quick composition adjustments and menu navigation despite being on the lower resolution side by today’s standards.

The Sony A7 III steps it up with a 3-inch tilting LCD boasting 922k-dot resolution, paired with a significantly more detailed 0.78x magnification EVF at 2359k-dot resolution. This makes it much easier to critically assess focus and exposure in bright outdoor conditions or complex lighting.

Neither camera offers a fully articulating screen, but their tilting designs accommodate most shooting angles with flexibility. Both support touch to focus and menu control, although the Sony’s menus remain more layered and sometimes time-consuming to navigate compared to Olympus’s more streamlined approach.

Lens Ecosystem: Micro Four Thirds Versatility vs Full-Frame Breadth

One of Olympus’s greatest strengths lies in its native Micro Four Thirds system. The E-M5 benefits from over 100 native lenses - many compact and cost-effective - plus the ability to adapt a wide variety of manual focus glass thanks to the short flange distance.

Sony E-mount lenses have grown steadily, now featuring about 120 native options spanning primes, zooms, and ultra-fast lenses. While full-frame glass tends to be bigger and pricier, the optical quality is generally stunning, especially for professional use.

If budget and portability are significant factors, Olympus lenses are often smaller, lighter, and friendlier to your wallet. Sony’s lens ecosystem caters more to those seeking premium optics for demanding professional work.

Paint with Light: Portraits and Bokeh Quality

Portrait photographers will notice immediate differences. The Sony’s larger sensor and ability to use fast prime lenses (often f/1.4 or f/1.8) yield creamy, natural bokeh with smooth subject isolation, a boon for flattering skin tones and eye sharpness.

Olympus’s crop sensor inherently provides deeper depth of field, so while you can still achieve subject-background separation with fast Olympus lenses, the “background melt” effect is never quite as pronounced.

In terms of skin tone rendition, both cameras handle color quite well, but the Sony’s broader dynamic range and color depth score (25 bits vs 22.8 bits on the E-M5) allow for more nuanced midtone transitions and smoother gradations. However, Olympus’s TruePic VI processor still delivers pleasing colors in JPEGs without much fuss.

Landscape and Travel: Resolution, Durability, and Mobility

Landscape shooters prioritize dynamic range, resolution, and weather resistance.

The Sony’s 24MP full-frame sensor captures more detail and a wider tonal range, preserving highlights and shadow detail more effectively. The camera itself is weather-sealed to handle damp, dusty, or chilly environments, making it well-suited to rugged outdoor use.

The Olympus also boasts environmental sealing but in a smaller, lighter platform optimized for travel. While its 16MP resolution tops out lower, micro four-thirds format tends to encourage lighter setups that are invaluable for hiking and handheld shooting in variable conditions.

Power users might appreciate the Sony’s longer battery life (610 shots vs 360 on Olympus) and dual SD cards, which reduce downtime and risk of data loss during extended field work.

Wildlife and Sports: Autofocus, Responsiveness, and Frame Rate

For wildlife and sports shooters chasing fast action, speed and tracking reliability are paramount.

The Sony A7 III’s 10 fps burst with full AF and 693 phase detection points gives a distinct edge in capturing fleeting moments. Its sophisticated tracking algorithms maintain sharp focus on erratic subjects ranging from birds in flight to athletes sprinting across fields.

The Olympus E-M5 struggles a bit here, with its 9 fps burst relying on contrast detection AF, making it less adept at consistently locking focus on fast-moving subjects, particularly in low-contrast scenes.

While Olympus’s crop sensor advantage gives a built-in telephoto reach bonus (2.1x focusing multiplier), it doesn’t entirely compensate for the superior AF performance and sensor sensitivity offered by Sony.

Street and Macro Photography: Discretion and Detail Work

Street shooters often prefer cameras with discreet operation and lightweight profiles. The Olympus E-M5’s smaller stature and silent shooting mode reduce intrusiveness - a bonus for candids or urban exploration. Its stabilized sensor also helps in low light without excessive ISO bumping.

For macro photography, neither camera is specialized, but both benefit from in-body 5-axis stabilization to keep handheld shots crisp. Olympus’s extensive lens range includes a variety of dedicated macro lenses that are compact and affordable.

Sony can handle macro just fine, but the need for larger lenses and the heavier body might be a turnoff for some.

Night and Astro Photography: High ISO and Exposure Flexibility

Sony’s higher maximum native ISO (51,200) and excellent noise performance at elevated sensitivity make it a strong contender for astrophotography and nighttime landscapes. The broader dynamic range protects highlights such as stars and moonlit foregrounds from clipping.

The Olympus E-M5 is respectable with native ISO capped at 25,600, but noise becomes more apparent past ISO 1600-3200, making long-exposure astro shots noisier. Its maximum shutter speed of 1/4000 sec is fairly standard but limiting if you want ultra-fast exposures.

Neither camera offers dedicated astro modes, but Sony’s time-lapse recording support gives creators more options for capturing the night sky.

Video Capabilities: 4K, Slow Motion, and Audio

Videographers might find the Sony A7 III more suitable. It supports 4K UHD recording at 30 fps, full HD at up to 120 fps for smooth slow-mo, and employs advanced codecs like XAVC S. The dedicated microphone and headphone jacks allow professional audio monitoring and input – essential for narrative work or serious vlogging.

Olympus E-M5 records in 1080p max at 60 fps, which is fine for casual video but lacks 4K support entirely. It also does not have microphone or headphone ports, limiting audio control.

If your video needs are casual or Instagram-focused, Olympus may suffice. For more polished productions, Sony’s video tools are markedly better.

Connectivity, Power, and Storage: Workflow and Convenience

Sony recognized the demands of modern shooters by integrating Wi-Fi, NFC, and Bluetooth - allowing quick wireless file transfers to smartphones or tethered shooting for studio work.

The Olympus E-M5 only supports Eye-Fi card connectivity, which is considerably more limiting compared to Sony’s built-in wireless ecosystem.

On battery life, Sony’s NP-FZ100 batteries offer almost double the capacity of Olympus’s BLN-1, critical in long shoots or travel scenarios where charging options are scarce.

Sony’s dual card slots provide added security and flexibility, while Olympus relies on a single SD card slot.

Price and Value: What You Get for Your Money

When these cameras launched, the Olympus E-M5 was priced around $799, positioning it as an advanced enthusiast camera affordable to many. Its smaller sensor and less complex AF system reflect that midrange placement.

The Sony A7 III came in as a flagship mirrorless for pros and serious enthusiasts at about $1,998, nearly two and a half times the Olympus’s price. This premium reflects the leap in sensor tech, autofocus, build quality, and video capabilities.

If you’re a cheapskate or beginner looking to learn on a solid advanced body, Olympus presents tremendous value with decent image quality and portability. However, for photographers seeking the best in low light, dynamic range, tracking, and professional video, the Sony’s price premium is justified in spades.

Summary of Strengths and Weaknesses

Olympus E-M5 Pros:

• Lightweight, compact design ideal for travel and street photography
• Robust 5-axis sensor stabilization
• Wide micro four-thirds lens ecosystem with many affordable options
• Weather-sealed magnesium alloy body
• Fast-enough 9 fps burst for casual action
• Affordable advanced mirrorless entry point

Olympus E-M5 Cons:

• Smaller sensor limits dynamic range and high ISO performance
• Contrast-detection AF less capable in tracking moving subjects
• Lower resolution EVF and LCD screen
• No 4K video or advanced audio inputs
• Single SD card slot and limited wireless features
• Shorter battery life

Sony A7 III Pros:

• Full-frame 24MP BSI-CMOS sensor with excellent detail and dynamic range
• Rapid hybrid AF with Eye AF and animal detection
• High native ISO and low noise performance, excellent for night and sports
• 4K video with advanced codec support and headphone/microphone jacks
• Dual SD card slots and robust connectivity (Wi-Fi, Bluetooth, NFC)
• Large battery capacity and professional-grade build quality
• Broad native lens selection covering all genres

Sony A7 III Cons:

• Heavier and larger to carry around
• Higher price may be prohibitive for budget shooters
• Complex menu system can slow down navigation
• Tilt-only screen (not fully articulating)

Olympus E M5 front Olympus E M5 screen back Sony A7 III front Sony A7 III screen back

Who Should Buy Which?

If you’re a:

• Travel or Street Photographer: The Olympus E-M5’s portability and quiet operation, combined with a versatile lens lineup, make it a perfect companion for lightweight kits. Budget-conscious shooters learning the ropes will appreciate the solid image quality and controls.

• Portrait Photographer: Sony’s full-frame sensor and advanced AF outperform the Olympus at delivering sharp eyes and beautiful bokeh. Pro-level resolution and color depth help you produce more polished results.

• Wildlife or Sports Shooter: Sony dominates with its 10 fps burst and hybrid AF tracking. The crop factor advantage of Olympus lenses is outweighed by Sony’s superior sensitivity and autofocus speed.

• Landscape Photographer: Sony’s larger sensor excels in dynamic range and detail capture for demanding landscapes. Olympus offers a decent alternative for hikers who can’t carry heavy gear and prefer smaller glass.

• Videographer: Sony A7 III hands down, thanks to 4K capture and professional audio input/output capability.

• Budget-Minded Enthusiasts: Olympus E-M5 still serves as an excellent entry point into advanced mirrorless photography without breaking the bank.

Final Verdict: Aligning Your Priorities

Choosing between the Olympus OM-D E-M5 and Sony A7 III boils down to knowing your shooting style, expectations, and budget.

The Olympus E-M5 remains a sprightly camera with a surprising array of features for its vintage and size - sensor stabilization, fast burst, weather sealing, and competent AF for its generation. It’s a favorite for enthusiasts who prize portability and affordability without demanding cutting-edge specs.

The Sony A7 III represents a generational leap forward - marrying professional full-frame image quality with a blazing AF system, excellent video tools, and solid battery life. It’s a reliable all-rounder that professionals trust in hectic environments, from the studio to the wild.

For me, if ultimate image quality, autofocus speed, versatility, and video functionality are priorities and budget allows, the Sony A7 III is the clear choice. However, if you want a powerful, compact mirrorless with a rich lens lineup and friendly price, especially if you prioritize travel or street use, the Olympus E-M5 still deserves a serious look.

Both cameras have proven their mettle in the real world; your job is to match their capabilities to your creative ambitions and financial realities. Happy shooting!