Sony A7 III vs Sony TX100V: An Expert Comparison for Enthusiasts and Pros

Choosing the right camera often boils down to your shooting style, needs, and budget. Today, I’m dissecting two very different beasts from Sony’s lineup: the mirrorless powerhouse Sony A7 III and the ultra-compact Sony TX100V. Both carry the Sony badge and boast appealing features, yet they serve vastly different photographic intents.

Having tested thousands of cameras across decades, I’ll guide you through an inclusive comparison, fleshing out how these two perform across varied photography disciplines, their tech nuances, real-world handling, and suitability for different users. You’ll find straightforward insights, backed by hands-on experience and thorough technical analysis - no fluff, just the stuff that helps you decide.

First Impressions and Ergonomics: Size, Weight, and Handling Matter

Before diving into pixels and pixels per inch, handling is often the first thing you notice. Here’s a visual that tells the story:

The Sony A7 III sports the classic SLR-style mirrorless form factor. Its robust (yet relatively compact) body measures 127 x 96 x 74 mm and weighs around 650 grams - comfortable for sustained handheld shooting. It strikes a balance between portability and a firm grip, giving you confident control with an extensive button layout.

In contrast, the Sony TX100V is one of those pocket-sized ultracompacts, a mere 97 x 59 x 18 mm and only 147 grams. Slip it into a jacket pocket or purse without noticing - ideal for days when carrying a bulky rig is a no-go. But obviously, the smaller size comes with compromises in handling and control precision.

For photographers who prioritize ergonomics and fast operation - especially in dynamic conditions - the A7 III’s body feels like a true professional tool. Meanwhile, the TX100V’s slim profile excels in discretion and ultra-casual ease. Both have tilting or fixed touchscreens, but the size disparity shapes how you’ll use them in practice.

Design Language and Control Layout: What’s Under Your Fingers?

Handling not only demands size but also the design of controls. Let’s peek at the top view to see these two side by side:

The A7 III owes its professional status to an intuitive and customizable control spread. Dedicated dials for shutter speed, exposure compensation, and an array of assignable buttons make it possible to adjust key settings on the fly. The electronic viewfinder (EVF), with its high resolution and magnification, sits at eye level - perfect for precise framing and shooting in challenging light.

On the other hand, the TX100V takes a minimalist approach. There are fewer direct controls, no EVF, and a reliance on touchscreen navigation for settings. This makes sense for a camera aimed at simplicity and casual use but limits flexibility for power users or in scenarios demanding quick adjustments.

So, if you like to tweak ISO, aperture, shutter speed manually or want quick access to specific functions without diving into menus, the A7 III clearly leads.

Sensor Technology and Image Quality: The Heart of the Camera

This is where the two cameras' DNA diverge most dramatically:

• The Sony A7 III features a full-frame 24 MP BSI-CMOS sensor measuring 35.8 x 23.8 mm. Full-frame sensors like this are prized for exceptional image quality - superior dynamic range, rich color depth (DxO Color Depth: 25.0), and excellent low-light performance (DxO low light ISO: 3730). The large sensor area (852.04 mm²) allows for better noise control and detailed captures, making it suitable for demanding professional and hobbyist work alike.

• Meanwhile, the Sony TX100V houses a tiny 1/2.3-inch (6.17 x 4.55 mm) 16 MP BSI-CMOS sensor. The sensor area shrinks to 28.07 mm² - a fraction of the full frame’s size. While this makes the camera decidedly more compact, it limits image quality. Highlights include decent color rendition and fairly good noise control for its class, but it can’t compete with the A7 III’s range or depth.

Raw format support further accentuates the A7 III’s professional edge. If you plan to do robust post-processing or print large, the full-frame sensor allows pristine results - crisp textures, good shadow detail, and smooth gradations.

The TX100V does not support raw files, which constrains editing latitude and is a critical consideration if you prefer a creative workflow involving software like Adobe Lightroom or Capture One.

In sum, the A7 III’s sensor is a game changer for almost every photographic application. The TX100V’s sensor is targeted at casual shooters where convenience outweighs ultimate image quality.

Performance in Key Photography Genres: Where Each Camera Excels

Let’s explore how each camera holds up across vital photography types. I refer to the test gallery below to highlight some sample imagery from both for visual context.

Sony A7 III front Sony A7 III screen back Sony TX100V screen back

Portrait Photography

The Sony A7 III’s full-frame sensor and advanced autofocus shine in portraiture. The 693 phase-detection AF points, wide coverage, and Eye AF (including animal eye detection) let you lock focus on eyes crisply and consistently, even in tricky scenes. The camera produces smooth, creamy bokeh thanks to large sensor size and compatibility with Sony’s superb G Master lenses.

Conversely, the TX100V offers modest portrait capabilities. Its fixed zoom lens with a max aperture of f/3.5-4.6 doesn’t provide as shallow a depth of field. Plus, its 9 autofocus points and lack of eye detection make precise focus challenging, especially in low light or on moving subjects.

Landscape Photography

Dynamic range and resolution are critical here. The A7 III’s 24 MP sensor pulls out outstanding detail and wide tonal ranges - perfect for landscapes, allowing pixel-level cropping for prints or digital use. Environmental sealing further invites shooting in varied outdoor conditions - from dusty beaches to humid forests.

The TX100V’s smaller sensor and 16 MP resolution produce decent snaps but with noticeably less latitude. There’s no weather sealing, so cautious handling is advised when shooting outdoors in less-than-ideal weather.

Wildlife Photography

Wildlife demands autofocus speed and tracking, long focal reach, and burst shooting.

• A7 III delivers with its 10 fps mechanical shutter burst and robust autofocus tracking (693 points + Eye AF). Paired with Sony’s extensive telephoto E-mount lenses (ranging from 70-200mm f/2.8 to super-tele zooms), it’s tailor-made for action-packed nature scenes.

• The TX100V’s fixed lens maxes out at 100mm equivalent, restricting reach. Its contrast-detect AF and lack of continuous AF or tracking hinder capturing fast-moving subjects.

Sports Photography

Here, speed and tracking accuracy rule.

The A7 III’s 10 fps burst rate combined with excellent AF tracking and stable IBIS (in-body image stabilization) makes it highly capable even in demanding sports environments - think indoor basketball or evening soccer matches.

The TX100V, despite its 10 fps capability, can’t sustain fast action due to limitations in AF system and shutter speeds maxing out at 1/1600 sec.

Street Photography

The TX100V excels at street photography for those seeking discretion. Its small footprint and quiet operation help you blend in seamlessly - perfect for spontaneous candid shots.

Meanwhile, the A7 III’s size and shutter noise might attract unwanted attention, but its superior low-light capability can capture dimly lit streets with finesse, albeit less discreetly.

Macro Photography

Neither camera offers dedicated macro features or focus stacking. However, the A7 III’s numerous compatible macro lenses and its advanced AF precision permit superior close-up work.

The TX100V’s minimum focus distance and zoom range limit true macro potential.

Night and Astrophotography

The A7 III’s large full-frame sensor, high maximum ISO 51200 (boostable to 204800), and low noise make it a strong contender in night photography and astrophotography. Manual exposure control allows for longer shutter times and creative star trails.

The TX100V’s max ISO 3200 and smaller sensor size constrain low-light shooting, resulting in more noise and lower detail.

Video Capabilities

The A7 III supports 4K UHD recording at 24p and 30p with 8-bit 4:2:0 internally and 4:2:2 externally, plus Full HD up to 120p for slow motion. It has microphone and headphone jacks, built-in 5-axis stabilization for handheld shooting, and intuitive video controls.

The TX100V sticks to Full HD 1080p at 60 fps max, lacks microphone or headphone ports, and offers optical stabilization only. Its video features suit casual use but fall short of professional standards.

Travel Photography

The TX100V’s pocketability and simplicity make it a great travel companion for snapshots and sightseeing. It has built-in GPS for location tagging, a feature the A7 III lacks.

If image quality and versatility are priorities, the A7 III wins hands down, though at the expense of size and weight.

Professional Work

The Sony A7 III clearly targets professionals and serious enthusiasts, supporting advanced workflows: dual cards for overflow/backup, full manual exposure modes, extensive lens choices, tethering capability, and raw formats.

The TX100V, an ultracompact geared towards consumers, lacks these professional workflow abilities.

Autofocus System Deep Dive: Precision and Speed

One of the A7 III’s defining strengths is its hybrid autofocus system combining 693 phase-detection and 425 contrast-detection points. This yields fast lock-on, reliable tracking across the frame, and superb Eye AF that powers portrait and wildlife specialists alike.

In contrast, the TX100V employs a simple 9-point contrast-detection AF system without face or eye detection, limiting both accuracy and effectiveness in photographing moving subjects or complex scenes.

If autofocus performance is your top priority, the A7 III is a clear winner.

Build Quality and Weather Sealing

The A7 III uses a magnesium alloy body with robust seals protecting against dust and moisture - not waterproof but built for challenging environments you might encounter outdoors.

The TX100V lacks weather sealing, relying on careful handling to avoid damage from environmental exposure.

This aspect reflects these cameras’ target demographics - the semi-professional hobbyist vs. casual user.

LCD Screens and Viewfinders

The A7 III provides a 3-inch tilting touchscreen with 922k dots, combined with a bright 2.36 million dot OLED EVF covering 100% frame.

The TX100V has a slightly larger 3.5" fixed touchscreen with an impressive 1229k dots and Sony’s XtraFine OLED TruBlack technology - excellent for daylight viewing but no viewfinder at all.

For composition precision and clarity under varied light, especially outdoor, the A7 III’s EVF is invaluable. The TX100V relies on the rear screen solely.

Battery Life and Storage Options

The A7 III features the NP-FZ100 battery rated for roughly 610 shots per charge, among the best in mirrorless cameras, and has dual card slots (SD + Memory Stick formats) for extended shooting and backup.

The TX100V uses a smaller NP-BN1 battery. Sony doesn’t specify shot count here, but typical usage often requires spare batteries for extended sessions. It has one card slot.

For extensive shooting days or professional work, A7 III’s superior endurance is essential.

Connectivity and Modern Features

The A7 III supports built-in Wi-Fi, Bluetooth, NFC, USB 3.1, and HDMI with clean output, making it ideal for tethered workflows, remote shooting, and fast content sharing.

The TX100V relies on earlier Eye-Fi compatibility for wireless transfers and lacks Bluetooth or NFC.

Comprehensive Performance Scores and Genre Analysis

Let’s not forget the empirical benchmarks:

You can see the Sony A7 III’s near-top-tier DxOmark overall sensor score of 96, outstanding dynamic range, depth, and low-light ISO - numbers that underscore why this camera is a workhorse for pros and enthusiasts.

The TX100V isn’t rated by DxOmark, reflecting its niche as an ultracompact where sensor performance isn’t the primary driver.

Lens Ecosystem and Compatibility

One major A7 III advantage - it accepts Sony E-mount lenses with over 120 options suitable for any genre: ultra-wide, prime, telephoto, macro, portrait, and specialty optics. This versatility is unbeatable.

The TX100V’s fixed zoom means you’re locked into its 25-100 mm equivalent f/3.5-4.6 lens. Compact as it is, it constrains creative framing and optical quality possibilities.

Price-to-Performance Ratio: Where Does the Money Go?

With a current retail price near $2000, the A7 III is a significant investment. However, its professional-grade sensor, autofocus, build, and lens compatibility offer long-term value.

The TX100V sells around $380 new but is discontinued, reflecting its role as a budget-friendly compact with decent image quality for casual snapping.

For those wanting a high-quality image creator and flexibility, the A7 III's price is justified. For easy-to-carry everyday shooting and social media snapshots, the TX100V represents excellent affordability.

So, Which Sony Is Right for You?

Summarizing the insights:

• Choose the Sony A7 III if:

  • You’re a budding or professional photographer needing full-frame image quality.
  • You shoot portraits, landscapes, wildlife, sports, or video at a high level.
  • You demand fast and versatile autofocus, weather resistance, and professional workflows.
  • You want extensive lens options and future-proofing your gear.
  • You prefer manual controls and customizable buttons.
  • Budget allows for a premium investment.

• Choose the Sony TX100V if:

  • You seek a truly pocketable, everyday carry camera for casual shooting.
  • You prioritize discretion, quick snaps, and simple operation over ultimate quality.
  • You are an enthusiast or traveler who wants GPS tagging and straightforward video.
  • Your budget is tight, or you want a secondary "grab and go" camera.
  • You don’t need interchangeable lenses or professional features.

Parting Thoughts: Two Cameras, Worlds Apart

This comparison might feel like putting apples against oranges. And to an extent, it is. The Sony A7 III is a professional-grade mirrorless camera that has redefined affordable full-frame capabilities since its release. The Sony TX100V, vintage by today’s standards, is a slice of Sony’s early 2010s ultracompact ingenuity designed for ease of use and portability.

Both hold value - but for fundamentally different reasons. If you crave image quality, autofocus performance, and versatility, the A7 III remains a top recommendation even years post-launch. For casual users craving pocket convenience with decent quality, the TX100V is a nostalgic, pragmatic choice, though newer compacts with updated tech might now be worth considering.

I hope this in-depth guide helps you better understand these two cameras. My experience with both Sony’s flagship and compact cameras shows that your choice hinges on your photographic ambitions and shooting style - as always, my best advice is to hold each in your hands, explore menus, and imagine your favorite shooting scenarios.

Happy shooting!

Feel free to explore more in my accompanying video review and sample image gallery for these cameras. The real-world examples underscore how each performs in typical situations.

If you have questions about specific disciplines or need further advice, I’m here to help. Just ask!