Olympus OM System OM-5 vs Sony A6400: An Expert’s Comprehensive Mirrorless Camera Showdown

Choosing between the Olympus OM System OM-5 and the Sony A6400 puts you in an interesting spot of the mirrorless market. Both are tailored for advanced users craving portability and performance, but they come with distinct philosophies and hardware strengths. Having personally pushed these cameras through diverse settings - from rugged landscapes and wildlife chases to studio portraits and city street shoots - I’m here to unpack how they truly perform where it counts.

Let’s peel back the layers, dive deep into specs and real-world experience, and help you find your perfect photographic match.

Form Factor & Ergonomics: Size and Handling for Long Shoots

First impressions matter, especially when you’ll be holding a camera for hours. The Olympus OM System OM-5 embraces a classic SLR-style mirrorless design with fully articulated touchscreen, while the Sony A6400 sports a more compact, rangefinder-style body with a tilting screen.

At 125x85x50 mm and 414 grams, the OM-5 is slightly chunkier than Sony’s 120x67x50 mm, 403-gram A6400. That extra girth translates to a more substantial grip on Olympus’s part, which I personally appreciate during extended handheld shooting or when outfitted with heavier lenses. The OM-5’s ergonomics strike me as a return to traditional camera handling - bold, well-contoured grip and intuitively placed buttons.

Looking at the top control layout, Olympus spreads out physical dials and buttons with a certain tactile confidence, including a dedicated exposure compensation dial and shutter speed dial for quick adjustments without diving into menus. Sony’s minimalist approach compacts controls on a smaller top plate, geared more towards enthusiasts comfortable with menu diving or customizable buttons.

If you value tactile dials and a robust hand-feel, especially outdoors, the OM-5 gains the upper hand here. For those chasing ultimate pocketability, Sony’s sleeker A6400 wins by a small margin.

Sensor Technology and Image Quality Foundations

At the heart of any camera is its sensor, and here’s where the two cameras diverge statistically and operationally.

The OM System OM-5 uses a 20MP Four Thirds sensor measuring 17.4x13 mm, resulting in a sensor area of about 226 mm². The Sony A6400 features a larger APS-C sensor at 23.5x15.6 mm, around 367 mm², with a 24MP resolution.

More pixels and a physically larger sensor typically deliver better high-ISO performance, higher dynamic range, and richer color depth. Sony’s APS-C sensor enjoys superior DxOMark ratings - color depth (24.0 bits), dynamic range (13.6 EV), and low-light ISO (1431) outpace what the OM-5 hardware reports (Olympus hasn’t had DxOMark scores published yet, but real-world testing aligns with typical Micro Four Thirds limitations).

In my tests, the OM-5’s images are clean and vibrant up to ISO 1600, but the A6400 extends usable ISO further, topping out effectively even beyond ISO 3200. Landscape and low-light shooters will notice the noise floor and tonal gradation benefits of the Sony sensor.

Autofocus Systems: Precision Meets Flexibility

Autofocus performance can make or break a shoot, especially with fast-moving subjects.

Olympus’s OM-5 employs a hybrid AF system with 121 focus points and includes phase and contrast detection, supported by face detection and eye AF (animal eye AF is absent). The A6400 pushes AF with 425 focus points and robust real-time tracking, including remarkable animal eye AF - a feature I’ve relied on extensively for wildlife shoots.

The OM-5 offers 10 fps mechanical and 30 fps electronic continuous shooting, which is quite impressive for a Micro Four Thirds sensor. The A6400 delivers 11 fps mechanical continuous shooting, but without an electronic shutter option for higher frame rates.

In practical wildlife photography tests, I found Sony’s tracking - especially for erratically moving subjects - far superior, with a higher keeper rate during bursts. Olympus performs admirably with static scenes and portraits but can struggle slightly to maintain focus on fast wildlife.

Body Durability and Weather Sealing for the Adventurer

If your camera’s travel bag goes on rugged treks or rainy shoots, durability and weather resistance become vital.

Both cameras feature some level of environmental sealing but lack explicit dustproof or waterproof ratings.

The OM-5 explicitly touts environmental sealing against moisture and dust, catering to the outdoor enthusiast. Sony’s A6400, while weather resistant, does not emphasize this as much in its marketing or design specs.

When I carried the OM-5 on mountain trails in light rain and dusty conditions, it performed without a hiccup. It feels like Olympus’s heritage in rugged models carries over well here.

Screen and Viewfinder: Composing Your Visual Story

For live view framing and menu navigation, screen quality and ergonomics matter a lot.

Olympus’s fully articulated 3-inch 1.04 million-dot touchscreen provides excellent flexibility for low or high-angle shooting. Its responsiveness to touch focus and menu interactions is fluid, ideal when composing portraits or macro shots at odd angles.

Sony’s 3-inch tilting touchscreen (0.92 million dots) tilts up and down but lacks full articulation. It’s selfie-friendly and works well for everyday shooting but less convenient for video vloggers or macro photographers needing more flexible framing.

Both cameras sport electronic viewfinders (EVFs) with around 2.36 million dots and 100% coverage. Sony holds a slight edge with 0.7x magnification versus Olympus’s 0.68x, offering a marginally larger view. In bright sunlight, both EVFs perform beautifully with bright vivid previews and minimal lag.

For me, the OM-5’s articulated screen often makes up for its slightly smaller EVF magnification in creative shooting.

Lens Ecosystem and Focal Length Factor

Lens choice determines how far your creativity and technique can stretch.

Olympus uses the Micro Four Thirds mount with an effective 2.1x focal length multiplier, meaning a 25mm lens behaves like a 52.5mm lens on full frame. Sony’s A6400 employs the Sony E-mount with a 1.5x crop factor, offering about 1-stop better low-light performance per sensor area and slightly wider fields of view on equivalent lenses.

Both mounts boast impressive native lens lineups - Olympus with roughly 119 lenses and Sony close at 121 lenses - covering everything from ultra-wide fisheyes to super telephotos. Olympus’s smaller sensor size means smaller, lighter lenses but with some reach penalty for wide-angle photography.

If you prioritize compact system size and long telephoto reach (e.g., bird photography), OM-5’s Micro Four Thirds lineup is hard to beat. For broader wide-angle options and superior low-light versatility, Sony’s APS-C ecosystem shines.

Battery Life and Storage Reliability: Powering Your Vision

Nothing ruins a shoot like a dead battery or a choke point in memory.

Sony’s A6400 handset holds a clear edge on battery life, rated for around 410 shots per charge (CIPA standard), compared to Olympus OM-5’s 310 shots.

Both cameras use single SD card slots, but Olympus supports the faster UHS-II standard, giving slight advantages for writing large RAW files or extended buffer clearing.

For longer outdoor shoots where power outlets are scarce, I recommend Sony’s A6400 or planning additional Olympus spare batteries.

Real-World Performance Across Photography Genres

Having examined specs, let’s see how they hold up in various genres. For visual sample comparison, see the gallery below.

OM System OM 5 front OM System OM 5 screen back Sony A6400 front Sony A6400 screen back

Portrait Photography: Skin Tones, Bokeh, and Eye AF

Sony’s superior 425-point AF array and real-time eye tracking (including animal eye AF) deliver reliable and quick focus in portrait settings. The APS-C sensor’s slightly shallower depth of field provides a creamier background blur, especially with fast primes.

Olympus, while competent, produces images with more depth of field given the smaller sensor, impacting bokeh. Still, OM-5’s color science renders skin tones very naturally and pleasantly, rivaling larger-sensor cameras with proper lens choices.

Landscape Photography: Dynamic Range and Resolution

Landscape shooters will appreciate Sony’s wider dynamic range and 24MP resolution, capturing fine textures and broad tonal gradation in shadows and highlights. The OM-5 provides great color rendition but lags in highlight retention on high-contrast scenes.

The OM-5’s better weather sealing and vibration sensor-based 5-axis image stabilization help handheld shooting stability, but for landscapes, tripod use remains standard.

Wildlife Photography: Autofocus Speed, Burst Rates, and Reach

Sony’s eye AF and 425-point AF array outperform Olympus especially under fast and erratic animal movements. The A6400’s 11 fps mechanical burst is trustworthy with sharper results on moving subjects.

Olympus’s 30 fps silent electronic shutter mode is enticing for discrete shoots but suffers from rolling shutter effects in certain lighting.

For telephoto reach, Olympus’s 2.1x crop factor extends your photographic reach, although the smaller sensor can be noisier at high ISO settings.

Sports Photography: Tracking Accuracy and Low Light Capability

Sony’s tracking AF and higher native ISO ceiling give it the edge for indoor sports or low-light arenas. The 11 fps burst complements timing critical action shots. The OM-5’s 10 fps and higher electronic shutter speeds provide flexibility but less responsive AF tracking.

Street Photography: Discreteness, Speed, and Portability

Both cameras are light and lend themselves to street shooters, but Olympus’s smaller grip and fuller articulation support shooting from waist level or unusual angles unnoticed. Sony is a touch more compact and faster to deploy due to excellent AF speed.

Macro Photography: Magnification and Focus Precision

While neither camera is specialized for macro, Olympus’s 5-axis sensor stabilization aids handheld macro work. Combined with the extensive Micro Four Thirds dedicated macro lens line, OM-5 is slightly more suited here.

Sony users will rely on stabilized lenses or tripods for optimal focus precision.

Night & Astro Photography: High ISO and Exposure Modes

Sony’s superior high ISO handling enables cleaner astro shots even at ISO 3200 and beyond. Live view exposure previews and bulb mode accessibility make star trails a joy to capture.

Olympus is capable of night photography but expect increased noise and manual patience.

Video Capabilities: 4K and Audio Features

Both models shoot 4K UHD video, with Olympus at 4K/24p (MOV, 237 Mbps) and Sony offering 4K/30p (XAVC S, 100 Mbps). The OM-5 supports sensor-based 5-axis stabilization for smoother handheld footage, whereas the A6400 lacks in-body stabilization, relying on lens-based or gimbal solutions.

Both have microphone inputs but no headphone jacks, a common budget mirrorless compromise.

Travel Photography: Versatility and Battery Life Balance

Here Sony’s longer battery life and slightly smaller size benefit travelers. Olympus’s weather sealing and articulating screen favor versatility in diverse shooting scenarios. Battery packs and charging options must be considered for longer adventures.

Professional Workflow Integration and Reliability

While neither is a flagship full-frame mirrorless with all professional bells and whistles, both offer raw file output, custom white balance, and exposure modes that fit serious workflows.

Sony’s solid DxO scores and larger sensor make it a more attractive backup camera for professionals, whereas Olympus’s rugged design is ideal for demanding environmental conditions.

Scoring and Final Performance Ratings

Summarizing test scores and real-world usage across criteria, Sony A6400 generally scores higher in image quality and AF accuracy, with Olympus OM-5 excelling in body ergonomics, stabilization, and outdoor durability.

Value for Money and Who Should Choose Which

Olympus OM System OM-5 – $1,199 MSRP

• Strong contender for photographers invested in Micro Four Thirds lenses
• Enthusiasts needing weather sealing, excellent stabilization, and versatile touchscreen
• Ideal for macro, rugged outdoor, landscape, and travel users prioritizing durability
• Slightly higher price but with advanced body features justifying cost

Sony A6400 – $898 MSRP

• Great APS-C image quality with larger sensor benefits
• Faster, more precise autofocus for wildlife, sports, and portraits
• Longer battery life and more lightweight for city, street, and travel photography
• Excellent all-rounder for enthusiasts needing budget-friendly professional-quality images

Final Thoughts: Which Mirrorless Camera Should You Buy?

If you’re primarily a landscape or wildlife enthusiast who demands fast, accurate autofocus and broader dynamic range, the Sony A6400 will likely satisfy your needs better, especially with its superior sensor size and AF capabilities. Add to that its attractive price and long battery stamina, and it becomes a formidable everyday camera.

On the other hand, if you want a camera that feels rugged, features excellent in-body stabilization, and offers a tactile, classic handling experience - all packaged in a well-weather sealed body - the Olympus OM System OM-5 may be your perfect companion. Its fully articulating screen, silent electronic shutter options, and excellent Micro Four Thirds lens ecosystem make it a standout for outdoor enthusiasts, travel shooters, and macro photographers.

In my experience, neither camera is a poor choice; rather, it boils down to your workflow, shooting genres, and ergonomic preference. Test handling both if possible, check your lens compatibility, and consider which features best align with your photographic vision.

Happy shooting!

If you want to see highlights from my hands-on testing and sample image comparisons, don’t miss the gallery above or my full video review linked below.