Sony
Alpha 7S III
12MP low-light video specialist with 4K 120p, 16-bit RAW HDMI, and excellent autofocus.
$3,499
Launch priceReleased Sep 2020
Sony
FX9
Full-frame 6K XDCAM camcorder with Dual Base ISO, S-Cinetone, Fast Hybrid AF, variable ND, and oversampled DCI 4K up to 60p.
$10,998
Launch priceReleased Sep 2019
Alpha 7S III is 1 year newer.
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Wins
Alpha 7S III
Wins
FX9
3 categories tied
Which would you choose?
TL;DR — Key differences
- AAlpha 7S III has higher Burst (mechanical) (10 fps vs 0 fps)
- AAlpha 7S III has higher Burst (electronic) (10 fps vs 0 fps)
- AAlpha 7S III has higher IBIS effectiveness (5.5 stops vs 0 stops)
- AAlpha 7S III has higher ISO max (native) (102,400 vs 4,000)
- AAlpha 7S III has lower ISO min (native) (80 vs 800)
Key specs at a glance
Size and weight, to scale
📸 Snap this size diff to shareAlpha 7S III
129 × 97 × 81 mm
699 g (1.54 lb / 24.66 oz)
Credit card
85.6 × 54 mm
for scale
FX9
146 × 143 × 229 mm
2000 g (4.41 lb / 70.55 oz)
Alpha 7S III is 17mm narrower, 46mm shorter, and 148mm thinner than FX9.
Alpha 7S III is 1301 g lighter than FX9.
Depth (front-to-back): 81mm Alpha 7S III · 229mm FX9
Sensor size, to scale
Alpha 7S III
35.6 × 23.8 mm · Full Frame
847 mm² area
FX9
35.7 × 18.8 mm · Full Frame
671 mm² area
1.3× 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
FX9
✓ 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
Burst (mechanical)
10 fps vs 0 fps — higher is better
Burst (electronic)
10 fps vs 0 fps — higher is better
Codecs
Adds XAVC HS, XAVC S, XAVC S-I…
IBIS effectiveness
5.5 stops vs 0 stops — higher is better
Dimensions (W×H×D mm)
Adds 128.9, 96.9, 80.8
ISO max (native)
102,400 vs 4,000 — higher is better
ISO min (native)
80 vs 800 — lower is better
Weight
699 g vs 2000 g — lower is better
Reasons to choose
FX9
Codecs
Adds XAVC-I, XAVC-L, MPEG HD422
Dimensions (W×H×D mm)
Adds 146, 142.5, 229
Card types
Adds XQD
Resolution
20.5 MP vs 12.1 MP — higher is better
Both cameras share
- ✓AA filter — Both support aa filter
- ✓AF frame coverage — Both 94 %
- ✓Eye AF — Both support eye af
- ✓Animal / bird AF — Both support animal / bird af
- ✓Weather sealing — Both support weather sealing
- ✓Card slots — Both 2
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
FX9
Pros
- ✓Full-frame 6K Exmor R oversampling
- ✓Dual Base ISO 800 / 4000
- ✓S-Cinetone + S-Log3
- ✓Built-in variable ND (1/4–1/128)
- ✓12G-SDI + dual XQD slots
Cons
- –Large shoulder-cam form factor
- –Body-only is 2 kg
- –XQD media (not CFexpress)
- –6K not recorded natively (oversampled 4K)
Decided which one is right for you?
Compare live prices for the Alpha 7S III and FX9 at major authorized retailers.
Sony Alpha 7S III
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Full specifications
✓ = category winner
Frequently asked
Quick answers generated from verified specs.
Which is better for travel, Alpha 7S III or FX9?
Alpha 7S III scores 6.5/10 versus 2.5/10 for FX9 — 699g — manageable for travel.
What's the resolution difference between the Alpha 7S III and FX9?
Alpha 7S III is 12.1 MP and FX9 is 20.5 MP, so the FX9 captures more detail for cropping and large prints.
Do the Alpha 7S III and FX9 have in-body image stabilization?
Alpha 7S III has 5.5-stop in-body image stabilization, while FX9 does not have IBIS.
What's the weight difference between the Alpha 7S III and FX9?
Alpha 7S III weighs 699 g and FX9 weighs 2000 g, so the Alpha 7S III is 1301 g lighter.
Do the Alpha 7S III and FX9 record 4K video?
Alpha 7S III: 4K up to 120p. FX9: 6K oversampled → DCI 4K / UHD 4K (max), 4K up to 60p.
Are the Alpha 7S III and FX9 weather sealed?
Alpha 7S III: Yes. FX9: Yes.
How much does each cost?
Alpha 7S III launched at $3,499 and FX9 at $10,998. The Alpha 7S III is $7,499 less.
Can't decide between two? Compare a third camera.
Add any camera to get a three-way Alpha 7S III vs FX9 vs X comparison.
Specs sourced from manufacturer data. Use-case scores algorithmically derived. Last reviewed June 2026.