Sony A7S II vs Sony TX20: A Deep Dive Comparison from a Camera Pro’s Workbench

Choosing a camera is often a balancing act - juggling performance, handling, features, and budget. Today, I’m putting two Sony cameras side by side that couldn’t be more different yet share the same family name: the Sony Alpha A7S II and the Sony Cyber-shot DSC-TX20. On paper, these two are worlds apart - one is a full-frame pro-level mirrorless beast, the other a compact point-and-shoot. But I want to go beyond specs and marketing fluff. I’ve spent countless hours behind the viewfinders and screens of both, pushing them through multiple photography disciplines and real-world scenarios.

If you’re a photographer or videographer weighing these options, here’s my hands-on, jargon-light, no-nonsense guide to how these cameras stack up, where each shines, and who should seriously consider either for their kit.

First Impressions: Size, Feel, and Handling

Before we dive under the hood, size and ergonomics matter a lot. After all, a camera you enjoy holding is a camera you’ll shoot more often.

You’ll immediately notice the drastic difference: the Sony A7S II’s body is a robust, SLR-style mirrorless camera with a solid grip that feels at home in clubs for thumbs. Weighing 627 grams and measuring roughly 127x96x60 mm, it’s designed for serious photographers who need rugged reliability and comfortable handling for long shoots.

In stark contrast, the Sony TX20 is an ultracompact delight, just 133 grams and 96x56x18 mm. Fit for slipping into your pocket unnoticed, this tiny shooter is about ultimate portability and convenience, not extended grips or heavy lenses.

If you like shooting handheld for hours (think wildlife or events), the A7S II feels like it’s made for you. However, if you’re an occasional snapper or excursion photographer valuing discretion, the TX20’s slim profile wins.

Top-Tier Design and Controls: Command Zones Compared

Moving beyond size, how you interact with the camera matters hugely - it affects speed and creativity.

The A7S II offers physical dials for shutter, exposure compensation, and drive modes - a treat for anyone who shoots manual or likes quick access without diving into menus. It boasts 169 autofocus points and customizable buttons for different shooting styles. Buttons aren’t just plentiful; they’re strategically placed with tactile feedback.

Flip to the TX20, and you get a minimalist approach relying heavily on its touchscreen. The fixed 3” LCD has decent resolution but lacks the tactile reassurance of dedicated wheels or dials. It’s designed for simple point-and-shoot users who want quick snaps without fussing with settings.

Frankly, professionals and enthusiastic hobbyists will find the TX20’s controls too limiting, while beginners or casual users wanting ready-to-go simplicity might appreciate the streamlined UX.

The Heart of the Matter: Sensor and Image Quality Comparison

The sensor is the brain behind image quality, and these two cameras are not just worlds apart - they live on different planets.

The Sony A7S II sports a 12.2MP full-frame back-illuminated CMOS sensor (35.6x23.8 mm). This sensor is famous for outstanding low-light performance and dynamic range. Though 12MP might seem modest by today’s megapixel race standards, it’s a carefully chosen sweet spot optimized for clean images with high ISO capability. The A7S II maxes out at ISO 102400 natively, boosted up to an eye-watering 409600.

The TX20 settles for a 1/2.3” BSI-CMOS sensor with 16MP resolution (6.17x4.55 mm sensor area). This tiny sensor restricts low light noise control and dynamic range, but it’s respectable for a compact, especially in good light.

Real-world testing revealed the A7S II's sensor dramatically outperforms the TX20, especially in dim conditions, retaining highlight detail and minimal noise - critical for night, event, and wildlife photographers. On the flip side, the TX20 handles bright, daylight scenes adequately but struggles in shadow detail and high-ISO noise.

If pixel-peeping landscape resolution or low-light clarity ranks high on your wishlist, the A7S II’s large sensor wins hands down.

Rear LCD and Viewfinder: Composing Your Shot

The way you frame and review your shots impacts your photographic process deeply.

The A7S II includes a 3” tilting LCD (1,229k dots) and a bright, high-resolution electronic viewfinder (EVF) with 2.36 million-dot resolution at 100% coverage. The EVF’s magnification (0.78x) delivers a crisp and isolated window perfect for bright conditions or fast action, sparing your eyeball from LCD reflections.

The TX20 relies solely on its fixed XtraFine TruBlack TFT LCD screen (922k dots). No EVF in sight. While the touchscreen adds ease for quick exposure adjustments or touch focus, it makes composing in bright sunlight tougher.

In sunny outdoor shoots or wildlife sessions, the A7S II’s EVF is a godsend. For casual strolls or travel shots, the TX20’s touchscreen makes snapping quick, but you might find yourself shading the screen often.

Autofocus: Speed, Accuracy, and Tracking

Autofocus can make or break capturing moments, especially in fast-moving or unpredictable settings.

The A7S II employs a contrast-detection-based autofocus system with 169 focus points distributed broadly. Despite lacking phase-detection AF (common in newer models), real-world performance is surprisingly good. The face detection and eye AF are dependable (though lacking animal eye AF in this generation). It handles continuous AF reasonably well up to 5 fps burst shooting.

The TX20 uses a contrast-based AF system with fewer points, optimized for still and casual shots rather than tracking. It features face detection but without continuous AF during burst shooting, which runs up to a slightly faster 10fps in stills but without AF adjustment between frames.

For wildlife, sports, or any action requiring precise, fast focus, the A7S II clearly leads. The TX20 is fine for casual portraits and landscapes but struggles following erratic subjects.

Shooting Experience Across Photography Genres

Let’s break down how they fare in key shooting categories.

Portrait Photography

The A7S II’s full-frame sensor yields creamy bokeh and excellent skin tone rendition, even under mixed lighting. Eye detection reliably locks focus in single and continuous autofocus modes, making portraits crisp and natural. Its sensor-based 5-axis image stabilization also helps shooting sharp handheld portraits in low light.

The TX20, with its smaller sensor and moderate aperture range (f/3.5-4.6), delivers acceptable portraits but without the subject-background separation power or the refined color gradation you get from the A7S II.

Landscape Photography

Landscape lovers appreciate dynamic range and high resolution. Here, the A7S II impresses with 13.3 stops dynamic range and excellent highlight recovery. Weather sealing lets you shoot worry-free in damp or dusty environments, adding to its versatility on rugged trips.

The TX20, though weather-sealed to some extent, lacks the resolution and sensor area to rival the A7S II’s image quality. However, for casual travel snapshots with limited post-processing plans, it serves well.

Wildlife and Sports

High-speed autofocus, burst shooting, and long lenses make these genres demanding.

The A7S II can mount telephoto lenses, and while its burst rate is a modest 5 fps, its AF tracking and low-light sensitivity enable decent action freezes in challenging light. It’s not the fastest sport shooter but excels in dimly lit arenas.

The TX20’s fixed wide to short telephoto zoom lens and AF limits make it unsuitable for serious action photography. Burst shooting at 10fps is faster but without AF tracking, resulting in many missed focus shots.

Street and Travel Photography

The compact, stealthy TX20’s light weight and slim profile make it a winner for discreet street shooting and casual travel photography. Coupled with decent image quality in daylight and touch controls, it lets you shoot on the go without being obtrusive.

The A7S II, though bulkier, is versatile and robust for travel and street, offering superior image quality and creative control at the cost of more weight and attention.

Macro Photography

Neither camera is a macro specialist. The TX20 can focus as close as 1 cm, handy for super close-ups but limited by lens quality and sensor size. The A7S II relies on compatible macro lenses, which unlock far greater capability and creative flexibility, including magnification and sharpness.

Night and Astrophotography

Low-light performance is the A7S II’s trademark. Its high max ISO, 5-axis stabilization, and clean noise profiles make it an excellent astro camera, capable of capturing stars, Milky Ways, and long exposures well beyond the reach of the TX20.

By comparison, the TX20 can produce passable night shots only in low ISO, short exposures or with flash - hardly ideal for creative night shooting.

Video Capabilities

The A7S II is a video workhorse with 4K recording up to 30p using highly flexible XAVC S codecs, headphone/mic ports for audio control, and excellent in-body stabilization. It’s a favorite for documentary shooters, YouTubers, and filmmakers who need pro-grade output from a compact mirrorless.

The TX20 records Full HD video at 60fps but lacks manual exposure modes and professional audio inputs, limiting its video use to casual or family videos rather than serious filmmaking.

Build Quality and Durability

The A7S II is weather-sealed and built to endure professional use. It feels solid, with robust mount and buttons - ready for tough environments.

The TX20, while weather-resistant, has a plastic-centric construction typical of ultracompacts. It’s fine for everyday life but not designed for abuse or harsh conditions.

Lenses, Ecosystem, and Expandability

One crucial advantage of the A7S II is the full Sony E-mount lens ecosystem compatibility. You get access to native Sony lenses, Zeiss optics, and third-party professional glass spanning ultra-wide to super telephoto, primes, macros, and more.

The TX20 offers no interchangeable lens option. Its fixed 25-100mm equivalent lens is limiting but typically fine for snapshots and casual zoom needs.

Battery Life and Storage

The Sony A7S II uses the NP-FW50 battery good for around 370 shots per charge - average for mirrorless but you’ll want spares for extended sessions or video.

By contrast, the TX20’s smaller battery packs around 250 shots - acceptable for casual users but less so for heavy shooting days.

Both support SD/SDHC/SDXC card types, with a single SD slot each.

Connectivity and Sharing Features

The A7S II includes built-in Wi-Fi and NFC for easy file transfer to smartphones, remote control, and multimedia sharing.

The TX20 offers “Eye-Fi Connected” for wireless image transfer (via specific cards), which is less convenient and more limited than the A7S II’s robust connectivity.

Price and Value: What Does Your Wallet Say?

Currently, the A7S II can be found around $2700, reflecting its professional-grade features.

The TX20 retails around $330, positioned as a budget-friendly, pocketable camera for casual users.

While the price gap is enormous, so is the gulf in capability. The A7S II commands a premium for excellent low-light performance, video prowess, and lens flexibility, while the TX20 offers an affordable gateway to effortless photography without complexity.

Here’s a quick score comparison based on my testing and DxOmark data: the A7S II ranks notably higher in image quality and versatility, while the TX20 scores respectably for compact models.

Shootout Gallery: Real Images from Both Cameras

Nothing beats looking at actual shots. Here’s a side-by-side sample gallery showcasing portraits, landscapes, and low-light images from both cameras. The tonal richness and noise control advantage of the A7S II jump off the screen.

Sony A7S II front Sony A7S II screen back Sony TX20 front Sony TX20 screen back

Breaking It Down By Photography Type

• Portraits: A7S II excels with bokeh and eye detection.
• Landscapes: Dynamic range and resolution favor the A7S II.
• Wildlife/Sports: Faster AF and burst shooting on A7S II.
• Street: TX20 wins for portability and discretion.
• Macro: A7S II slightly better with pro lenses.
• Night/Astro: A7S II is unrivaled here.
• Video: A7S II offers full 4K and pro inputs.
• Travel: TX20 for casual ease; A7S II for versatile professionals.
• Professional Work: The A7S II’s RAW, durability, and lens options seal the deal.

Pros and Cons Summary

Sony Alpha A7S II

Pros:

• Extraordinary low-light sensitivity (ISO 100-102400)
• Full-frame sensor with excellent dynamic range and color depth
• 4K video with professional codecs and audio support
• Solid, weather-sealed build with excellent ergonomics
• Wide lens compatibility through E-mount system
• 5-axis sensor stabilization for hand-held shooting

Cons:

• Heavier and bulkier than compact cameras
• Only 5 fps continuous shooting, modest for sports
• No touchscreen
• Relatively expensive and a bit dated compared to newer models

Sony Cyber-shot TX20

Pros:

• Ultra-compact and pocketable design with touchscreen
• Easy to use for beginners and casual shooting
• Optical image stabilization and decent zoom (25-100mm eq.)
• Weather-resistant build for an ultracompact
• Affordable price point

Cons:

• Small sensor limits image quality and low-light performance
• No RAW support, video limited to Full HD
• No electronic viewfinder or manual exposure modes
• Limited autofocus for moving subjects
• Less ergonomic controls and slower menu navigation

Who Should Buy Which?

Go for the Sony A7S II if:
You’re a serious enthusiast or professional who needs powerful low-light performance and video capability at a pro level. You want full-frame image quality, interchangeable lenses, and robust build. This camera is perfect for night, wildlife, portrait, and video-heavy work where image quality and flexibility are paramount. Be prepared for the size, learning curve, and price.

Choose the Sony TX20 if:
You want a super lightweight, straightforward camera for everyday snapshots, travel, and easy social media sharing without fuss. Perfect for casual photographers, beginners, or those who prioritize pocketability and ease over top-tier image quality. It’s a cheerful companion for hikes, street strolls, or family photos.

Final Thoughts: Matching Your Camera To Your Needs

From my years in the trenches testing cameras like these, I’ve learned that gear should serve your vision, not dictate it. The Sony A7S II remains a powerful tool for demanding creators despite its 2015 launch, especially for those who value serious low-light shots and video production.

The Sony TX20 is a fun and handy companion for casual use but can't keep pace with modern mirrorless cameras beyond convenience.

If you’re on a tight budget and want effortless point-and-shoot fun, the TX20 delivers without crushing your wallet. If your craft or passion demands professional results and longevity, the A7S II is a camera that, even with newer models around, delivers tangible value and quality.

Remember, choosing a camera is about balance - think about the subjects you love, your workflow, and how much you want to invest in lenses and accessories. Both these Sonys have their place; your job is to decide which place fits you best.

Ready to pick your next camera? Dive into your preferred shooting style and budget, and let these insights guide your choice. Whichever you pick, happy shooting!