OM System
OM-3 ASTRO
Astrophotography-focused OM-3 variant with 20.4MP stacked sensor, H-alpha-friendly filter tuning, IP53 sealing, and 7.5-stop Sync IS.
$2,499
Launch priceReleased Jul 2025
Sony
Alpha 9 III
Global shutter sports flagship with 120fps and zero rolling shutter for pro action.
$5,999
Launch priceReleased Jan 2024
OM-3 ASTRO is 1.4 years newer.
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Wins
OM-3 ASTRO
Wins
Alpha 9 III
1 categories tied
Which would you choose?
TL;DR — Key differences
- AOM-3 ASTRO has higher Burst (mechanical) (10 fps vs 0 fps)
- AOM-3 ASTRO has higher ISO max (native) (102,400 vs 25,600)
- BAlpha 9 III has higher Max video bit rate (600 Mbps vs 150 Mbps)
- BAlpha 9 III has higher EVF resolution (9,437,184 vs 2,360,000)
- AOM-3 ASTRO has lower ISO min (native) (80 vs 250)
Key specs at a glance
Size and weight, to scale
📸 Snap this size diff to shareOM-3 ASTRO
139 × 89 × 46 mm
496 g (1.09 lb / 17.50 oz)
Credit card
85.6 × 54 mm
for scale
Alpha 9 III
136 × 97 × 83 mm
703 g (1.55 lb / 24.80 oz)
OM-3 ASTRO is 8mm shorter and 37mm thinner than Alpha 9 III but it is also 3mm wider.
OM-3 ASTRO is 207 g lighter than Alpha 9 III.
Depth (front-to-back): 46mm OM-3 ASTRO · 83mm Alpha 9 III
Sensor size, to scale
OM-3 ASTRO
17.4 × 13 mm · Compact / large-type
226 mm² area
Alpha 9 III
35.6 × 23.8 mm · Full Frame
847 mm² area
3.7× larger sensor area = shallower depth of field and better low-light performance.
Lens ecosystem
Native lens selection
OM-3 ASTRO
Micro Four Thirds
130+
native lenses available
Alpha 9 III
✓ 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
OM-3 ASTRO
AF low-light limit
-8 EV vs -5 EV — lower is better
Subject recognition
Adds People, Birds, Animals…
Burst (mechanical)
10 fps vs 0 fps — higher is better
Dimensions (W×H×D mm)
Adds 139.3, 88.9, 45.8
ISO max (native)
102,400 vs 25,600 — higher is better
ISO min (native)
80 vs 250 — lower is better
Card types
Adds SD UHS-I
Battery life (CIPA)
640 shots vs 400 shots — higher is better
Reasons to choose
Alpha 9 III
Subject recognition
Adds Human, Animal, Bird…
Dimensions (W×H×D mm)
Adds 136.1, 96.9, 82.9
Max video bit rate
600 Mbps vs 150 Mbps — higher is better
EVF resolution
9,437,184 vs 2,360,000 — higher is better
Codecs
Adds XAVC HS, XAVC S, XAVC S-I
AA filter
Only Alpha 9 III supports it
4K max frame rate
120 fps vs 60 fps — higher is better
Internal RAW video
Only Alpha 9 III supports it
Both cameras share
- ✓Eye AF — Both support eye af
- ✓Animal / bird AF — Both support animal / bird af
- ✓Burst (electronic) — Both 120 fps
- ✓Pre-Capture / Pre-Release — Both support pre-capture / pre-release
- ✓In-body stabilization (IBIS) — Both support in-body stabilization (ibis)
- ✓Weather sealing — Both support weather sealing
Pros & cons at a glance
Editorially curated highlights and trade-offs.
OM-3 ASTRO
Pros
- ✓Astro-tuned sensor filter
- ✓20.4MP stacked BSI Live MOS
- ✓IP53 weather sealing
- ✓7.5-stop Sync IS
Cons
- –Specialized astro variant
- –Micro Four Thirds sensor
- –Premium price
Alpha 9 III
Pros
- ✓Global shutter 120fps
- ✓Zero rolling shutter
- ✓Pro sports AF
- ✓Pre-capture buffer
Cons
- –24.6MP only
- –Premium price
- –Battery drain at max speed
Decided which one is right for you?
Compare live prices for the OM-3 ASTRO and Alpha 9 III at major authorized retailers.
OM System OM-3 ASTRO
Sony Alpha 9 III
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Full specifications
✓ = category winner
Frequently asked
Quick answers generated from verified specs.
Which is better for landscape, OM-3 ASTRO or Alpha 9 III?
Alpha 9 III scores 7.0/10 versus 2.5/10 for OM-3 ASTRO — Full-frame sensor — wider dynamic range.
What's the resolution difference between the OM-3 ASTRO and Alpha 9 III?
OM-3 ASTRO is 20.4 MP and Alpha 9 III is 24.6 MP, so the Alpha 9 III captures more detail for cropping and large prints.
Do the OM-3 ASTRO and Alpha 9 III have in-body image stabilization?
OM-3 ASTRO has 6.5-stop in-body image stabilization, while Alpha 9 III has 8-stop in-body image stabilization.
Which shoots faster bursts — the OM-3 ASTRO or the Alpha 9 III?
OM-3 ASTRO reaches 120 fps electronic. Alpha 9 III reaches 120 fps electronic.
What's the weight difference between the OM-3 ASTRO and Alpha 9 III?
OM-3 ASTRO weighs 496 g and Alpha 9 III weighs 703 g, so the OM-3 ASTRO is 207 g lighter.
Do the OM-3 ASTRO and Alpha 9 III record 4K video?
OM-3 ASTRO: 4K up to 60p. Alpha 9 III: 4K up to 120p.
Are the OM-3 ASTRO and Alpha 9 III weather sealed?
OM-3 ASTRO: Yes. Alpha 9 III: Yes.
Which has better battery life?
Rated battery life is 640 shots (CIPA) for the OM-3 ASTRO and 400 shots for the Alpha 9 III, giving the OM-3 ASTRO the edge.
How much does each cost?
OM-3 ASTRO launched at $2,499 and Alpha 9 III at $5,999. The OM-3 ASTRO is $3,500 less.
Can't decide between two? Compare a third camera.
Add any camera to get a three-way OM-3 ASTRO vs Alpha 9 III vs X comparison.
Specs sourced from manufacturer data. Use-case scores algorithmically derived. Last reviewed June 2026.