Sony A550 vs Sony RX100 IV

Choosing the right camera can be a formidable task, especially when you’re comparing two models that come from the same brand but cater to very different photographic needs. Today, I’m diving deep into a head-to-head comparison of the Sony Alpha DSLR-A550 and the Sony RX100 IV. Both are products of Sony’s impressive innovation but represent distinct design philosophies: one, a traditional entry-level DSLR designed around versatility with interchangeable lenses, and the other, a large sensor compact camera that marries portability with advanced tech. After extensively testing these two, here’s everything you need to know to decide which suits your photography style best.

A Tale of Two Sony Cameras: Size and Ergonomics First Impressions

Handling each of these cameras immediately reveals their design intentions. The Sony A550, announced back in 2009, embodies the classic DSLR form factor with a solid grip and substantial heft. By contrast, the RX100 IV, released six years later, is a compact powerhouse emphasizing portability without compromising on sensor performance.

The A550 tiptoes into the ‘compact SLR’ category, with dimensions measuring roughly 137mm wide, 104mm tall, and 84mm deep, and weighs 632 grams with battery. This size comfortably accommodates an extensive physical control layout - more on that shortly - and a familiar optical pentamirror viewfinder. Its solid-bodied feel translates to confidence in hand, especially during lengthy shoots.

On the other hand, the RX100 IV boasts an incredibly pocketable profile at just 102 x 58 x 41 mm and weighing 298 grams. This represents less than half the weight of the A550, making it a companion that’s easier to carry everywhere, even tucked into a jacket pocket. Its fixed lens and streamlined controls support quick point-and-shoot operation but naturally trades some tactile feedback for this compactness.

If your photography often involves travel or street shooting, and you prefer a camera that doesn’t scream “photographer,” the RX100 IV’s sleek design will appeal. Conversely, if you appreciate the deliberate heft and handling advantages of a DSLR for steady grip and extended sessions, the A550 has you covered.

Controls and Top-Plate Layout: Commanding Your Shots with Precision

Ergonomics extend beyond grip size to the control scheme, which affects how quicker and intuitive your shooting experience becomes.

Reviewing the top views side-by-side, the A550 showcases a traditional DSLR control architecture: a mode dial coupled with dedicated buttons for ISO, metering, and exposure compensation. There’s a command dial near the shutter button, allowing swift manual adjustments - a critical feature for anyone venturing beyond full auto modes.

The RX100 IV’s top plate is more minimalist but still thoughtfully arranged to let you navigate menus and shooting modes easily. You’ll find a mode dial, shutter button, and a zoom toggle on the lens barrel. However, because it targets enthusiasts who want both portability and flexibility, some controls are buried in menus rather than exposed in buttons. For photographers keen on rapid manual exposure changes, the A550’s layout is more immediately tactile.

I’ve tested both in fast-paced environments, and found the A550’s control layout slightly quicker to configure mid-shoot, especially when using manual exposure modes. The RX100 IV rewards you with simplified controls that keep distractions minimal, great for casual or travel photography.

Sensor Technology and Image Quality: Balancing Resolution, Size, and Performance

Let’s get into the heart of any camera: the sensor. A quick glance at their specs reveals stark differences that influence image quality and versatility.

The Sony A550 features a 14.2MP APS-C sized CMOS sensor measuring 23.4 x 15.6 mm. This sensor size is substantial and a hallmark of entry-level DSLRs, offering strong dynamic range and color depth. Based on Sony’s older Bionz processor, the A550’s sensor still holds up for many photographic genres, especially those prioritizing detail retention and nuanced color gradations.

Meanwhile, the RX100 IV boasts a 1-inch (13.2 x 8.8 mm) BSI-CMOS sensor with 20.1MP resolution. The back-illuminated (BSI) design helps improve low-light sensitivity in a sensor smaller than APS-C but optimized for better noise performance.

In practical terms, the A550’s larger sensor area (365 mm² vs. 116 mm²) means greater light gathering capability and a natural advantage in producing shallow depth-of-field effects - a trait especially valuable for portrait and macro photographers. Its dynamic range rating (11.8 EV) and color depth (21.9 bits) still remain respectable, although not cutting-edge by today’s standards.

The RX100 IV delivers higher resolution but packs those pixels into a smaller area, which can push noise levels upward under low light, even if BSI technology partially offsets this. Its dynamic range (12.6 EV) and color depth (22.9 bits) are impressive for a compact but don’t quite equal a full APS-C sensor’s latitude.

For landscape and studio photographers needing maximum image quality, the A550 will generally provide more flexibility in post-processing. However, for travel and everyday shooting where convenience and resolution matter most, the RX100 IV’s sensor remains one of the best in compacts.

Viewing and Composing Your Shots: Display and Viewfinder Experience Compared

Framing your shot accurately is crucial, so let’s see how these cameras stack up on display and viewfinder technology.

The A550 has a 3-inch tilting LCD with 922k dots resolution and an optical pentamirror viewfinder covering approximately 95% of the frame with 0.53x magnification. The tilting screen is a boon for low- or high-angle shooting, but the pentamirror finder is somewhat dimmer and less sharp compared to higher-spec pentaprisms, which you’ll see on more prosumer DSLRs.

Contrast that with the RX100 IV’s bright 3-inch 1.23 million dot tilting screen, sharper and more vibrant with better contrast. Even more impressive is its 2.36 million dot OLED electronic viewfinder, offering 100% frame coverage and about 0.59x magnification. This EVF is clear, detailed, and refreshes without noticeable lag, delivering a view very close to what your final image will look like - including exposure preview and white balance adjustments in real time.

For quick composition and reviewing focus, the RX100 IV’s EVF wins hands down - especially in challenging lighting. However, some photographers prefer the optical clarity and zero lag of an optical viewfinder like the A550’s, particularly in fast-action shooting or in lower battery situations where using the LCD and EVF might drain juice faster.

Image Samples and Real-World Performance Tests

Sample images tell a richer story than specs alone, so I’ve gathered examples shot side-by-side for you to judge quality and rendition.

Sony A550 front Sony A550 screen back Sony RX100 IV front Sony RX100 IV screen back

In portraits, the A550’s larger sensor and traditional DSLR lenses produce smoother skin tones and more pleasing bokeh around subject edges, capitalizing on the 50mm f/1.8 equivalent lenses I tested. Eye autofocus worked well but wasn’t as instantaneous or reliable as modern systems.

The RX100 IV, while limited to its built-in 24-70mm equivalent lens, surprisingly delivered sharp portrait shots with attractive background separation and well-handled skin tone rendition, aided by its fast lens aperture (F1.8-F2.8). Eye AF is present and extremely quick in this camera, improving subject tracking.

Landscape photos from the A550 exhibited slightly richer color depth and wider tonal range, thanks to the sensor size and higher dynamic range. Greens and blues rendered more naturally, with fine textures preserved in shadow detail. The RX100 IV’s images were clean and detailed but occasionally clipped subtle highlight nuances under harsh sunlight.

When it comes to burst shooting and autofocus tracking - key for wildlife and sports - the A550 performs respectably with its phase detection autofocus and 7 fps burst rate, although focusing centers mainly on a 9-point system without cross-type focus points. Tracking fast-moving subjects is manageable but requires some user patience.

The RX100 IV, despite smaller sensor and less advanced AF technology (focus points number at 25, contrast-detection only), achieves an impressive 16 fps burst with continuous AF, offering snappy shutter speeds and excellent subject tracking for a compact camera.

What About Autofocus, Stabilization, and Low Light Shooting?

Autofocus and stabilization are often overlooked until you’re in the thick of shooting demanding scenes.

The A550 sports a hybrid AF system with phase-detection autofocus points for speed and live view contrast-detection AF for accuracy. However, AF tracking remains rudimentary, lacking the sophisticated algorithms you’d find in later models. The inclusion of sensor-based image stabilization is a plus, mitigating shake by shifting the sensor - a welcome benefit when combined with older lenses that don’t include optical stabilization.

The RX100 IV uses optical image stabilization built into its lens assembly and boasts a highly responsive 25-point AF system employing contrast detection, supplemented by a fast hybrid system that can lock on subjects quickly. It includes advanced face detection with continuous AF tracking that’s surprisingly dependable for such a small sensor. Low light focusing is excellent down to around -1 EV.

In my tests, the RX100 IV’s autofocus felt snappier in low light and quick-action scenarios, while the A550 provided solid but more traditional AF performance better suited to less frantic shooting.

Video Recording and Multimedia Capabilities

If you shoot video, this comparison gets especially one-sided.

The A550 is strictly a stills camera with no video recording capability, sticking to what it does best: photos. This limits its versatility in today’s hybrid content landscape.

The RX100 IV shines here with 4K UHD recording at 30p, multiple frame rate options in 1080p (including 60p and 120p slow-motion), and various professional-friendly video codecs (AVCHD, XAVC S). While it lacks external mic and headphone jacks, it does provide built-in ND filters and precise exposure controls catering to videographers and advanced enthusiasts.

If video is on your plate, the RX100 IV is clearly the superior choice, offering advanced features packed into a pocket-friendly body.

Durability, Weather Sealing, and Battery Life

Both cameras target enthusiasts and are built modestly for their categories. Neither offers formal environmental sealing, so shooting in rain or dustier settings demands extra caution.

The A550’s heft and DSLR body mean it's naturally more rugged feeling. Battery life is impressive here, rated at up to 480 shots per charge using the optical viewfinder, making it a reliable workhorse on trips or events.

The more compact RX100 IV carries a lighter battery with a maximum rated 280 shots, which feels tight when shooting intensively or video, though carrying spare batteries mitigates this.

Lens Ecosystem and Compatibility

Here’s a huge deciding factor: the A550 supports Sony’s Minolta Alpha mount with compatibility to over 140 lenses. This includes legacy Minolta glass, modern Sony A-mount lenses, and third-party options. This unlocks creative potential, from tilt-shift lenses to super-telephoto glass - ideal for portraits, sports, wildlife, and macro photography.

The RX100 IV, in contrast, has a fixed 24-70 mm F1.8-2.8 zoom lens, versatile for its size but limiting if you crave ultra-telephoto reach or specialized optics. What you gain is simplicity and lightweight convenience.

Connectivity, Storage, and Workflow Integration

In terms of connectivity, the A550 includes USB 2.0 and HDMI ports but lacks wireless features, so image transfer relies on cables or card readers.

The RX100 IV improves on this with built-in Wi-Fi and NFC, support for mobile apps for remote control and image transfer, making it friendlier for social sharing and remote shooting.

Both use single card slots, supporting SD and Memory Stick formats - the norm but with no dual slots for backup.

Pricing and Value Overview

At launch pricing, the A550 was about $749, and the RX100 IV around $898. Naturally, the RX100 IV commands a premium for its compact design, cutting-edge sensor, and video prowess.

For those on a tighter budget prioritizing photographic exploration with diversity of lenses and image quality, the A550 offers great value. The RX100 IV justifies its price if you seek pocket convenience, video features, and high-speed autofocus in a no-fuss package.

How Each Camera Performs Across Photography Genres

• Portraits: A550’s sensor size and lens flexibility provide superior skin tones and bokeh. RX100 IV performs well but limited by lens focal range.
• Landscapes: A550 edges with dynamic range and resolution; RX100 excels in portability.
• Wildlife: A550’s lens options and phase-detect AF have the edge. RX100 fast burst and AF are impressive but focal length limits.
• Sports: A550’s 7 fps and 9 AF points are solid, RX100’s 16 fps burst impresses but with contrast AF limits.
• Street: RX100 IV’s discretion, size, and silent shutter excel; A550 is bulkier and noisier.
• Macro: A550 with dedicated lenses shines. RX100 IV’s 5 cm macro focus is useful but less flexible.
• Night/Astro: A550’s sensor performs better in low light; RX100’s BSI sensor competes but noise rises earlier.
• Video: RX100 IV is the clear winner.
• Travel: RX100 IV’s size, zoom, and connectivity make it ideal.
• Professional Work: A550’s lens mount, RAW support, and manual controls better suited.

Final Verdict: Which Sony Is Right for You?

Both the Sony A550 and RX100 IV are excellent in their niches, designed six years apart for different photographers.

• Choose the Sony A550 if you want a solid, affordable entry-level DSLR offering a vast lens ecosystem, good image quality especially for portraits and landscapes, longer battery life, and traditional DSLR handling. It’s best for enthusiasts who value creative flexibility and don’t mind the extra gear bulk.

• Opt for the Sony RX100 IV if you prioritize absolute portability, excellent video features, superior autofocus speed, and need a versatile all-in-one camera for travel, street photography, and casual video work without changing lenses.

In my experience, neither camera feels outdated in its realm. The A550 still delivers images that can stand alongside modern day APS-C models with a creative lens arsenal, while the RX100 IV remains a compact marvel that shatters typical limitations of point-and-shoot cameras.

Closing Thoughts

When I test cameras, I always ask myself: “Does this make photography easier, more enjoyable, or produce measurably better results for the intended user?” The A550, as a DSLR, rewards patience and commitment with nuanced imaging and professional handling. The RX100 IV appeals to those needing speed, mobility, and multimedia functions without doling out DSLR baggage.

Whichever camera you lean toward, consider your shooting scenarios carefully. What genres thrill you? How important is portability versus lens versatility? Can you invest in lenses or prefer an all-in-one tool? I hope my detailed comparison clears the fog and helps you reach a confident choice.

Happy shooting!