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Sigma

BF

Minimalist full-frame L-mount body with large top screen and unique design.

$1,999

Launch price

Released Apr 2024

vs

Sony

Alpha 9 III

Global shutter sports flagship with 120fps and zero rolling shutter for pro action.

$5,999

Launch price

Released Jan 2024

BF is 3 months newer.

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Wins

3categories

BF

WildlifePortrait

Wins

12categories

Alpha 9 III

Sports & ActionWildlife

3 categories tied

Which would you choose?

TL;DR — Key differences

BF wins 1 categories·Alpha 9 III wins 4 categories
  • ABF has higher Burst (mechanical) (6 fps vs 0 fps)
  • BAlpha 9 III has higher AF points / zones (759 vs 49)
  • BAlpha 9 III has higher Burst (electronic) (120 fps vs 15 fps)
  • 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)

Key specs at a glance

BFAlpha 9 III
Resolution24.2 MP24.6 MP
SensorFull FrameFull Frame
ISO max25,60025,600
Burst15 fps120 fps
4K60 fps120 fps
IBIS6-stop8-stop
Weight720 g703 g
Battery640 shots400 shots

Size and weight, to scale

BF

138 × 98 × 88 mm

720 g (1.59 lb / 25.40 oz)

Credit card shown to scale as a size reference (ISO 7810, 85.6 × 54 mm)

Credit card

85.6 × 54 mm

for scale

Alpha 9 III

136 × 97 × 83 mm

703 g (1.55 lb / 24.80 oz)

BF is 2mm wider, 1mm taller, and 5mm thicker than Alpha 9 III.

BF is 17 g heavier than Alpha 9 III.

Depth (front-to-back): 88mm BF · 83mm Alpha 9 III

Sensor size, to scale

BF

36 × 24 mm · Full Frame

864 mm² area

Alpha 9 III

35.6 × 23.8 mm · Full Frame

847 mm² area

Lens ecosystem

Native lens selection

BF: mount data unavailable

Alpha 9 III

✓ more lenses

Sony E

350+

native lenses available

80 first-party270 third-party

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

Use caseBFAlpha 9 III
Portrait
7.5Good
7.5Good
Sports & Action
6.5Good
10.0Excellent✓ wins
Video & Hybrid
6.0Good
8.0Excellent✓ wins
Landscape
7.0Good
7.0Good
Travel
7.5Good✓ wins
7.0Good
Wildlife
8.0Excellent
9.5Excellent✓ wins
Vlogging
5.5Fair
5.5Fair

Why pick one over the other

Reasons to choose

BF

  • Burst (mechanical)

    6 fps vs 0 fps — higher is better

  • Dimensions (W×H×D mm)

    Adds 138, 98, 88

  • ISO min (native)

    100 vs 250 — lower is better

  • Battery life (CIPA)

    640 shots vs 400 shots — higher is better

  • Subject recognition

    Adds Vehicle

Reasons to choose

Alpha 9 III

  • Dimensions (W×H×D mm)

    Adds 136.1, 96.9, 82.9

  • AF points / zones

    759 vs 49 — higher is better

  • Burst (electronic)

    120 fps vs 15 fps — higher is better

  • Max video bit rate

    600 Mbps vs 150 Mbps — higher is better

  • EVF resolution

    9,437,184 vs 2,360,000 — higher is better

  • RAW buffer depth

    200 frames vs 60 frames — higher is better

  • Codecs

    Adds XAVC HS, XAVC S, XAVC S-I

  • Subject recognition

    Adds Insect, Car/Train, Airplane

Both cameras share

  • AA filterBoth support aa filter
  • ISO max (native)Both 25,600
  • Eye AFBoth support eye af
  • Animal / bird AFBoth support animal / bird af
  • Pre-Capture / Pre-ReleaseBoth support pre-capture / pre-release
  • In-body stabilization (IBIS)Both support in-body stabilization (ibis)

Pros & cons at a glance

Editorially curated highlights and trade-offs.

BF

Pros

  • Unique design
  • Full-frame
  • L-mount

Cons

  • No IBIS
  • Niche ergonomics
  • Limited controls

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 BF and Alpha 9 III at major authorized retailers.

Affiliate disclosure: As an Amazon Associate, Cameraegg earns from qualifying purchases. Cameraegg may also earn commission from B&H links, at no extra cost to you.

Full specifications

= category winner

BF
Alpha 9 III
Resolution
24.2 MP
24.6 MP+2%
Sensor type
Full Frame CMOS
Full Frame Global Shutter Exmor RS CMOS
Sensor size
36.0 × 24.0 mm
35.6 × 23.8 mm
AA filter
Yes
Yes
BF
Alpha 9 III
Processor
Image processor
BIONZ XR + AI processing unit
BF
Alpha 9 III
ISO min (native)
100−150 less
250
ISO max (native)
25,600
25,600
ISO max (expanded)
102,400
51,200
BF
Alpha 9 III
Shutter type
Mechanical + Electronic
Global electronic shutter
Max mechanical speed
1/8000 sec
Max electronic speed
1/16000 sec
1/80000 sec

Frequently asked

Quick answers generated from verified specs.

Which is better for sports, BF or Alpha 9 III?

Alpha 9 III scores 10.0/10 versus 6.5/10 for BF — 120fps burst — pro-level action capture.

What's the resolution difference between the BF and Alpha 9 III?

BF is 24.2 MP and Alpha 9 III is 24.6 MP, so the Alpha 9 III captures more detail for cropping and large prints.

Do the BF and Alpha 9 III have in-body image stabilization?

BF has 6-stop in-body image stabilization, while Alpha 9 III has 8-stop in-body image stabilization.

Which shoots faster bursts — the BF or the Alpha 9 III?

BF reaches 15 fps electronic. Alpha 9 III reaches 120 fps electronic.

What's the weight difference between the BF and Alpha 9 III?

BF weighs 720 g and Alpha 9 III weighs 703 g, so the Alpha 9 III is 17 g lighter.

Do the BF and Alpha 9 III record 4K video?

BF: 4K up to 60p. Alpha 9 III: 4K up to 120p.

Are the BF and Alpha 9 III weather sealed?

BF: Yes. Alpha 9 III: Yes.

Which has better battery life?

Rated battery life is 640 shots (CIPA) for the BF and 400 shots for the Alpha 9 III, giving the BF the edge.

How much does each cost?

BF launched at $1,999 and Alpha 9 III at $5,999. The BF is $4,000 less.

Can't decide between two? Compare a third camera.

Add any camera to get a three-way BF vs Alpha 9 III vs X comparison.

Specs sourced from manufacturer data. Use-case scores algorithmically derived. Last reviewed July 2026.