Sony
Alpha 7S III
12MP low-light video specialist with 4K 120p, 16-bit RAW HDMI, and excellent autofocus.
$3,499
Released Sep 2020
Sony
FX30
Super 35 cinema camera with 4K 120p and affordable entry to Sony Cinema Line.
$1,799
Released Sep 2022
FX30 is 2 years newer.
Wins
Alpha 7S III
Wins
FX30
6 categories tied
TL;DR — Key differences
- AAlpha 7S III has higher ISO max (native) (102,400 vs 32,000)
- BFX30 has higher Resolution (26 MP vs 12.1 MP)
- AAlpha 7S III has higher RAW buffer depth (120 frames vs 60 frames)
- AAlpha 7S III has higher AF points / zones (759 vs 495)
- AAlpha 7S III has lower ISO min (native) (80 vs 100)
Key specs at a glance
Size and weight, to scale
Alpha 7S III
129 × 97 × 81 mm
699 g (1.54 lb / 24.66 oz)
FX30
130 × 78 × 85 mm
646 g (1.42 lb / 22.79 oz)
Alpha 7S III is 1mm narrower and 4mm thinner than FX30 but it is also 19mm taller.
Alpha 7S III is 53 g heavier than FX30.
Depth (front-to-back): 81mm Alpha 7S III · 85mm FX30
Sensor size, to scale
Alpha 7S III
35.6 × 23.8 mm · Full Frame
847 mm² area
FX30
23.3 × 15.5 mm · APS-C
361 mm² area
2.3× larger sensor area = shallower depth of field and better low-light performance.
Lens ecosystem
Native lens selection
Alpha 7S III
✓ more lensesSony E
350+
native lenses available
FX30
✓ more lensesSony E
350+
native lenses available
Counts include current first-party and major third-party native autofocus lenses.
Use-case scoring
Which one for what?
Algorithmic scores from verified specs · 10 = best in class
Why pick one over the other
Reasons to choose
Alpha 7S III
AF low-light limit
-6 EV vs -3 EV — lower is better
Dimensions (W×H×D mm)
Adds 128.9, 96.9, 80.8
ISO max (native)
102,400 vs 32,000 — higher is better
AA filter
Only Alpha 7S III supports it
RAW buffer depth
120 frames vs 60 frames — higher is better
AF points / zones
759 vs 495 — higher is better
ISO min (native)
80 vs 100 — lower is better
IBIS effectiveness
5.5 stops vs 5 stops — higher is better
Reasons to choose
FX30
Dimensions (W×H×D mm)
Adds 129.7, 77.8, 84.5
Resolution
26 MP vs 12.1 MP — higher is better
Weight
646 g vs 699 g — lower is better
Both cameras share
- ✓AF frame coverage — Both 94 %
- ✓Eye AF — Both support eye af
- ✓Animal / bird AF — Both support animal / bird af
- ✓Burst (mechanical) — Both 10 fps
- ✓Burst (electronic) — Both 10 fps
- ✓4K max frame rate — Both 120 fps
Pros & cons at a glance
Editorially curated highlights and trade-offs.
Alpha 7S III
Pros
- ✓Best-in-class low light
- ✓4K 120p
- ✓Full-size HDMI
- ✓Strong IBIS
Cons
- –12MP stills limit
- –Older generation now
- –No 8K
FX30
Pros
- ✓4K 120p
- ✓Affordable cinema
- ✓Active cooling
- ✓Log profiles
Cons
- –Super 35 crop
- –26MP stills crop
- –No full-frame
Full specifications
✓ = category winner
Frequently asked
Quick answers generated from verified specs.
Which is better for travel, Alpha 7S III or FX30?
FX30 scores 8.0/10 versus 6.5/10 for Alpha 7S III — 646g — compact and travel-friendly.
What's the resolution difference between the Alpha 7S III and FX30?
Alpha 7S III is 12.1 MP and FX30 is 26 MP, so the FX30 captures more detail for cropping and large prints.
Do the Alpha 7S III and FX30 have in-body image stabilization?
Alpha 7S III has 5.5-stop in-body image stabilization, while fX30 has 5-stop in-body image stabilization.
Which shoots faster bursts — the Alpha 7S III or the FX30?
Alpha 7S III reaches 10 fps electronic. FX30 reaches 10 fps electronic.
What's the weight difference between the Alpha 7S III and FX30?
Alpha 7S III weighs 699 g and FX30 weighs 646 g, so the FX30 is 53 g lighter.
Do the Alpha 7S III and FX30 record 4K video?
Alpha 7S III: 4K up to 120p. FX30: 4K up to 120p.
Are the Alpha 7S III and FX30 weather sealed?
Alpha 7S III: Yes. FX30: Yes.
Which has better battery life?
Rated battery life is 600 shots (CIPA) for the Alpha 7S III and 570 shots for the FX30, giving the Alpha 7S III the edge.
How much does each cost?
Alpha 7S III launched at $3,499 and FX30 at $1,799. The FX30 is $1,700 less.
Specs sourced from manufacturer data. Use-case scores algorithmically derived. Last reviewed May 2026.