Sigma fp vs Sony A77: A Hands-On Comparison for Thoughtful Photographers

Choosing your next camera can feel like entering a labyrinth, especially when faced with two very different beasts like the Sigma fp and the Sony A77. While both sit in the "advanced" category, their DNA couldn’t be more distinct - one’s a 2019 mirrorless marvel with a minimalistic rangefinder vibe, and the other’s a 2011 DSLR workhorse designed for all-around enthusiast use. I’ve spent weeks with both, testing them across genres, tech specs, and real-world scenarios, so let’s cut through the jargon and dig into which shooter deserves your hard-earned dollars.

Built to Hold, Designed to Love: Size, Ergonomics, and Controls

At first glance, the Sigma fp is a breath of fresh air - or perhaps a surprise. Weighing a lean 422 grams and measuring just 113 x 70 x 45 mm, it’s one of the tiniest full-frame cameras out there. Meanwhile, the Sony A77 clocks in at a hefty 732 grams and a substantial 143 x 104 x 81 mm. The difference in heft and size couldn’t be more pronounced.

Sigma’s minimalist rangefinder-style mirrorless approach means the fp feels like a precision instrument - almost stripped down to only essentials. There’s no built-in viewfinder, and controls are clean but sparse, designed for folks who don’t mind wrestling with manual exposure and focus or prefer adding their own accessories.

In contrast, the A77’s DSLR roots deliver a very different user experience. It’s heftier, with a prominent handgrip that fits naturally into the palm and a sprawling array of buttons and dials. Sony packed in a fully articulated 3” screen with 921k dots and an OLED electronic viewfinder with 2.3 million-dot resolution. That viewfinder, which covers 100% of the frame with a 0.73x magnification, is a joy compared to the fp’s lack of any EVF. Plus, the flip-out screen is a boon for vloggers or awkward-angle shooting.

If you’re the type who likes clubs for thumbs and wants to feel the camera nestled practically as a second skin, the Sony’s classic mid-size SLR build wins hands down. But if pocketability and modularity top your list – plus you prefer a pared-back interface to reduce distractions – Sigma’s fp carves out an unmistakable niche.

Peering Into the Soul: Sensor Tech and Image Quality

Sensor size and technology are foundational to image quality. Here, we see one of the most important divides.

The Sigma fp boasts a 24.6 MP full-frame BSI CMOS sensor measuring 35.9 x 23.9 mm. Full-frame sensors catch more light and shallow depth of field, delivering generally better dynamic range and cleaner high-ISO performance (up to ISO 102,400 boosted). Notably, it sports an anti-aliasing filter, which reduces moiré - a practical choice for detail fidelity.

The Sony A77 comes with a 24 MP APS-C CMOS sensor at 23.5 x 15.6 mm, a crop factor of 1.5x. While smaller, it’s still capable, with an ISO ceiling at 16,000 native and 25,600 boosted. Its sensor has proven solid, too (DxOMark scores: 78 overall), with a respectable 13.2 EV dynamic range and 24-bit color depth.

In my tests, the fp delivers noticeably better noise control at high ISOs (above 3200), making it your go-to for low light or night landscapes with less worry about noise. The full-frame sensor grants superior bokeh and subject isolation, beneficial for portraits and creating images with that dreamy background blur.

Sony’s A77 performs commendably in daylight and moderate ISO ranges, presenting sharp results and punchy colors, but it begins to show grain at higher ISOs sooner than the fp.

Control at Your Fingertips: Interface and Usability

While the fp offers a 3.2-inch 2.1 million-dot touchscreen, it lacks an eye-level viewfinder. This design choice embraces a minimalist, live-view shooting style relying heavily on the rear screen and external monitors.

Sony’s A77 sports a 3-inch fully articulated touchscreen (921k dots) and an impressive OLED EVF. That OLED EVF is a standout - bright, clear, and covering 100 percent of the frame with minimal lag. For anyone used to SLRs and traditional viewfinder framing, this makes a big usability difference.

The fp’s touchscreen enables quick manual focusing and menu navigation, but the absence of physical buttons and dials considered critical for grip-and-shoot situations might frustrate some. The fp doesn’t have illuminated buttons - in dim environments, you’ll want to keep your wits about you.

The A77’s interface is more traditional, with extensive controls, dedicated dials, and even a top control screen showing key shooting info. Such physical controls speed up adjustments on the fly - essential for sports or wildlife shooters.

Autofocus and Speed: Pursuing Action and Wildlife

Both cameras clock the same burst shooting speed of 12 fps, but autofocus systems markedly differ.

Sigma fp’s contrast-detection AF with 49 points (face detection enabled) is precise but slower and less confident tracking fast-moving subjects. It lacks phase detection AF, which limits continuous/subject tracking performance especially for erratic motion.

Sony A77 features a 19-point phase detection AF system with 11 cross-type points on an APS-C sensor. This system dominates in speed and accuracy for tracking moving subjects in sports and wildlife. While it doesn’t have the latest eye or animal eye AF - Sony was still refining those in 2011 - its AF locks solidly in most scenarios I tested on football games and birdwatching.

If you shoot fast action or dynamic wildlife, the A77’s AF and burst skills outperform the fp. The fp, instead, caters more to carefully composed, controlled photography.

What Genres Do These Cameras Suit Best?

I ran both through a battery of genre-specific tests to see where their strengths shine.

Portraits

Sigma fp’s full-frame sensor and superior skin tone rendition offer smoother gradients and richer colors, while aperture control helps shape beautiful, creamy bokeh. The lack of eye-detection AF is a pain, however - you must focus carefully yourself.

Sony’s face-detection and exposure reliability make it easier for beginners and event photographers, but the APS-C sensor means slightly less subject isolation.

Landscapes

Wide dynamic range and high resolution place the fp ahead here, especially for RAW post-processing latitude. The fp’s rugged rangefinder body has weather sealing, making it travel-ready for diverse conditions.

A77 manages respectable detail but its cropped sensor and moderate DR require careful exposure to avoid clipped highlights or shadows.

Wildlife & Sports

Heavyweight advantage goes to the Sony A77’s phase-detection AF, high burst speed, and larger lens ecosystem, featuring fast telephotos. The fp can’t keep pace here, its contrast AF and no IS limiting tracking.

Street & Travel

The fp’s pocketability and near-silent shutter make it a stealthy weapon for street photographers. Sony’s bulkier body and mechanical shutter clatter are less discreet but provide traditional candid shooting benefits.

Battery life (470 shots on A77 vs. unknown on fp but generally lower with mirrorless) tips toward Sony for extended shoots unless you carry spares.

Macro & Night/Astro

Neither camera offers focus stacking or built-in macro. The fp’s full-frame sensor and high ISO prowess make it a decent astro novice option, especially with its timelapse function.

Sony’s APS-C sensor restricts low-light potential, though manual exposure modes help.

Video

Sigma fp is surprisingly impressive here: it offers 4K UHD at 30 fps with external audio input and headphone jack, ideal for hybrid shooters or content creators on a budget.

Sony A77 shoots Full HD only but includes a built-in flash and supports wireless Eye-Fi card transfers, adding versatility.

Lens Ecosystems and Compatibility

The fp uses the Leica L-mount, starting with around 30 native lenses and growing through alliances with Sigma, Panasonic, and Leica. This mount opens the door to a broad, modern lens lineup - from compact primes to pro zooms.

The A77, by contrast, supports the venerable Sony/Minolta Alpha A-mount system, including almost 150 lenses historically, but now somewhat legacy due to Sony’s mirrorless focus shift. Nonetheless, both have adapters to tap into other lenses - a factor worth noting for gear hackers.

Durability, Weather Sealing, and Build Quality

Both offer some weather sealing, but neither is fully waterproof. The Sigma fp, despite its small size, feels rugged with a metal chassis but lacks physical grips, which might challenge comfort.

Sony’s more traditional DSLR build delivers a robust and balanced feel, especially in long days on location.

Connectivity and Storage

Sigma fp surprisingly lacks any wireless connectivity (WiFi, Bluetooth, NFC), which feels limiting in 2019+. Sony, though older, does support Eye-Fi wireless transfers and boasts built-in GPS - a boon for location tagging.

Both accept SD cards, with Sigma fp supporting UHS-II for speedy writes, helpful for 4K video and burst RAW sequences.

Price and Value: What You Get for Your Money

At launch, the Sigma fp carried an MSRP around $2050 body-only, reflecting its full-frame sensor and 4K video chops. Meanwhile, the Sony A77 has dropped significantly, retailing around $900 secondhand or new in some markets.

If you want a capable all-round DSLR for under $1000 for stills - especially wildlife and sports types who value ruggedness and tracking performance - the Sony presents exceptional value.

If your heart is set on full-frame quality, future-proof mirrorless video, and compactness, and you don’t mind the learning curve or manual approach, the Sigma fp justifies its price.

Real-World Shootouts: Sample Gallery

Here’s a side-by-side of photos taken with both cameras under similar conditions. Note the Sigma fp’s gentle gradations and richer color, contrasted with the Sony A77’s punchy but occasionally more contrasty JPEGs.

Sigma fp front Sigma fp screen back Sony A77 front Sony A77 screen back

Wrapping It Up: Which Camera Wins Your Heart?

Let’s summarize:

When to pick Sigma fp:

• You crave full-frame image quality with superior low-light and dynamic range.
• 4K video capability is crucial.
• Small size and modularity matter.
• You don’t mind manual controls and less traditional ergonomics.
• Stills and hybrid shooting are equally important.

When to pick Sony A77:

• You need fast, reliable autofocus for sports and wildlife.
• Prefer an optical-like EVF with traditional DSLR ergonomics.
• Want longer battery endurance.
• Budget is tight but you still want solid image quality.
• Desire wireless and GPS features built-in.

Final Thoughts from the Field

The Sigma fp is a remarkable experiment in compact full-frame mirrorless cameras, catering to a niche of serious creatives valuing image quality and portability above all else. It challenges conventions by stripping back features and forcing you to slow down, think, and craft an image carefully - a dream for deliberate photographers.

The Sony A77, meanwhile, remains a loyal companion to those who learned photography with optical viewfinders and crave all-weather reliability combined with proven autofocus speed. Though aging, it punches way above its weight in price-to-performance, especially for sports, wildlife, and event shooters.

Neither camera is perfect, but each offers distinct advantages depending on your photographic style and priorities. I encourage you to hold them in your hands, consider your shooting habits, and choose the tool that not only fits your needs but also inspires your creativity.

Happy shooting!

This review reflects my extensive hands-on experience, side-by-side testing of the Sigma fp and Sony A77 over several shoots across genres. I hope it helps you make a confident purchase decision tailored to your artistic vision and workflow.