GFX 50S IIvs Pentax K-3 Mark IIIvs Sigma fp
Pentax
Pentax K-3 Mark III (2021)
From £1699
Best for DSLR enthusiasts & outdoor photographers
View Pentax K-3 Mark III
Sigma
Sigma fp (2019)
From £1499
Best for Creative filmmakers & experimental photographers
View Sigma fp
Which should you buy?
Studio & Portrait Specialists — GFX 50S II (2021): Medium format quality at the most accessible price ever — 51MP detail and tonal richness no APS-C or full-frame body can replicate.
Dslr Enthusiasts & Outdoor Photographers — Pentax K-3 Mark III (2021): The finest APS-C DSLR ever made — class-leading weather sealing, optical viewfinder, 5-axis IBIS, and extraordinary build for photographers committed to DSLR.
Creative Filmmakers & Experimental Photographers — Sigma fp (2019): The smallest full-frame camera in the world — Cinema DNG RAW and L-mount flexibility in a pocket-sized body that rewards creative shooters.
Who should buy what
GFX 50S II (2021)
- You want to experience medium format without a five-figure investment
- You shoot landscape, architecture, or portraits where resolution and tonal depth matter
- You're in the Fujifilm ecosystem and want to step up to a larger sensor
Pentax K-3 Mark III (2021)
- You're a committed DSLR photographer with significant investment in Pentax glass
- You shoot in extreme weather conditions and place build quality and reliability above everything
- You prefer optical viewfinder performance and want the best modern APS-C DSLR available
Sigma fp (2019)
- You're a filmmaker building a cinema rig where the smallest full-frame body is essential
- You want L-mount compatibility to pair with Sigma Art or Leica SL lenses
- You prioritise video and cinema colour over stills ergonomics and functionality
Quick take: The gfx 50s ii has the highest resolution at 51mp; the sigma fp is the most affordable; only the gfx 50s ii, pentax k-3 mark iii are weather sealed. Scroll down for the full spec breakdown.
Full specifications
| Specification | GFX 50S II (2021) | Pentax K-3 Mark III (2021) | Sigma fp (2019) |
|---|---|---|---|
| Price | £2,999 | £1,699 | £1,499 |
| Sensor | 51.4MP Medium Format GFX 44×33mm BSI CMOS | 25.7MP APS-C BSI CMOS (AA-filterless) | 24.6MP full-frame Bayer CMOS |
| Resolution | 51.4MP | 25.7MP | 24.6MP |
| Video | 4K/30p (cropped) | 4K/30p, 1080p/60p | 12-bit Cinema DNG RAW, 4K/24p, 1080p/120p |
| Autofocus | Phase-detect, 425 points | SAFOX 13 phase-detect, 101-point (25 cross-type) | Contrast-detect AF with face/eye detection |
| Stabilisation | 5-axis IBIS, 6.5 stops | 5.5-stop 5-axis IBIS (Shake Reduction III) | None (lens-based only) |
| Burst Rate | 3fps | 12fps | 18fps electronic |
| Battery Life | ~440 shots (CIPA) | 800 shots (CIPA) | 200 shots (CIPA) |
| Weight | 900g body only | 820g body only | 422g body only |
| Dimensions | 150.0 × 104.2 × 87.2mm | 134.5 × 103.5 × 73.5mm | 112.6 × 69.9 × 45.3mm |
| Weather Sealed | Yes | Yes | No |
| Viewfinder | EVF, 3.69M dots, 0.77× magnification | Optical pentaprism, 100% coverage, 1.05× magnification | None |
| Screen | 3.2" tilting touchscreen | 3.2" tilting touchscreen | 3.15" fixed touchscreen |
| Mount | Fujifilm G-mount (medium format) | Pentax KF-mount | Leica L-mount |
| Memory Cards | Dual SD UHS-II slots | Dual SD UHS-II | Single SD UHS-II + CFexpress Type B (via adapter) |
| Connectivity | USB-C, Bluetooth, Wi-Fi | USB-C, Wi-Fi, Bluetooth | USB-C 3.1, Wi-Fi, Bluetooth |
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