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Pentax

645Z

51MP medium format DSLR that made digital MF accessible — still prized for landscape and studio.

$8,499

Launch price

Released Apr 2014

vs
Alpha 1 II

Sony

Alpha 1 II

50MP stacked flagship with 30fps RAW, 8K video, and Sony's fastest hybrid performance.

$6,499

Launch price

Released Nov 2024

Alpha 1 II is 10.6 years newer.

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Wins

4categories

645Z

WildlifeLandscape

Wins

12categories

Alpha 1 II

Sports & ActionVideo & Hybrid

2 categories tied

Which would you choose?

TL;DR — Key differences

645Z wins 0 categories·Alpha 1 II wins 5 categories
  • BAlpha 1 II has higher AF points / zones (759 vs 101)
  • BAlpha 1 II has higher EVF resolution (9,437,184 vs 3,690,000)
  • BAlpha 1 II has higher 4K max frame rate (120 fps vs 60 fps)
  • BAlpha 1 II has higher EVF refresh rate (240 Hz vs 120 Hz)
  • BAlpha 1 II has lower Weight (743 g vs 1470 g)

Key specs at a glance

645ZAlpha 1 II
Resolution51.4 MP50.1 MP
Sensor43.8 × 32.8 mmFull Frame
ISO max25,60032,000
Burst20 fps30 fps
4K60 fps120 fps
IBIS7-stop8.5-stop
Weight1470 g743 g
Battery640 shots520 shots

Size and weight, to scale

645Z

156 × 117 × 123 mm

1470 g (3.24 lb / 51.85 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 1 II front view

Alpha 1 II

136 × 97 × 83 mm

743 g (1.64 lb / 26.21 oz)

645Z is 20mm wider, 20mm taller, and 40mm thicker than Alpha 1 II.

645Z is 727 g heavier than Alpha 1 II.

Depth (front-to-back): 123mm 645Z · 83mm Alpha 1 II

Sensor size, to scale

645Z

43.8 × 32.8 mm · Medium Format

1437 mm² area

Alpha 1 II

35.9 × 24 mm · Full Frame

862 mm² area

1.7× larger sensor area = shallower depth of field and better low-light performance.

Lens ecosystem

Native lens selection

645Z: mount data unavailable

Alpha 1 II

✓ 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 case645ZAlpha 1 II
Portrait
6.0Good
8.5Excellent✓ wins
Sports & Action
6.5Good
10.0Excellent✓ wins
Video & Hybrid
6.0Good
9.5Excellent✓ wins
Landscape
8.0Excellent
9.0Excellent✓ wins
Travel
5.5Fair
6.0Good✓ wins
Wildlife
9.0Excellent
9.5Excellent✓ wins
Vlogging
5.5Fair
5.5Fair

Why pick one over the other

Reasons to choose

645Z

  • Dimensions (W×H×D mm)

    Adds 156, 117, 123

  • ISO min (native)

    64 vs 100 — lower is better

  • Subject recognition

    Adds Vehicle

  • Battery life (CIPA)

    640 shots vs 520 shots — higher is better

  • AF frame coverage

    100 % vs 94 % — higher is better

  • Resolution

    51.4 MP vs 50.1 MP — higher is better

Reasons to choose

Alpha 1 II

  • AF low-light limit

    -4 EV vs -3 EV — lower is better

  • Dimensions (W×H×D mm)

    Adds 136.1, 96.9, 82.9

  • AF points / zones

    759 vs 101 — higher is better

  • EVF resolution

    9,437,184 vs 3,690,000 — higher is better

  • Codecs

    Adds XAVC HS, XAVC S, XAVC S-I

  • Subject recognition

    Adds Insect, Car/Train, Airplane

  • 4K max frame rate

    120 fps vs 60 fps — higher is better

  • Internal RAW video

    Only Alpha 1 II supports it

Both cameras share

  • AA filterBoth support aa filter
  • Eye AFBoth support eye af
  • Animal / bird AFBoth support animal / bird af
  • Pre-Capture / Pre-ReleaseBoth support pre-capture / pre-release
  • Max video bit rateBoth 150 Mbps
  • In-body stabilization (IBIS)Both support in-body stabilization (ibis)

Pros & cons at a glance

Editorially curated highlights and trade-offs.

645Z

Pros

  • 51MP medium format
  • CMOS sensor
  • Pentax color
  • Relatively affordable MF

Cons

  • Huge body
  • Slow operation
  • Limited lens line vs Hasselblad

Alpha 1 II

Pros

  • 50MP stacked sensor
  • 30fps blackout-free burst
  • 8K 30p video
  • Best Sony AF

Cons

  • Very expensive
  • Complex menus
  • Large files

Decided which one is right for you?

Compare live prices for the 645Z and Alpha 1 II at major authorized retailers.

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Full specifications

= category winner

645Z
Alpha 1 II
Resolution
51.4 MP+3%
50.1 MP
Sensor type
Medium Format CMOS
Full Frame Stacked Exmor RS CMOS
Sensor size
43.8 × 32.8 mm
35.9 × 24.0 mm
AA filter
Yes
Yes
645Z
Alpha 1 II
Processor
Image processor
BIONZ XR + AI processing unit
645Z
Alpha 1 II
ISO min (native)
64−36 less
100
ISO max (native)
25,600
32,000+0.3 stops
ISO max (expanded)
102,400
102,400
645Z
Alpha 1 II
Shutter type
Mechanical + Electronic
Mechanical + Electronic
Max mechanical speed
1/8000 sec
1/8000 sec
Max electronic speed
1/16000 sec
1/32000 sec

Frequently asked

Quick answers generated from verified specs.

Which is better for sports, 645Z or Alpha 1 II?

Alpha 1 II scores 10.0/10 versus 6.5/10 for 645Z — 30fps burst — pro-level action capture.

What's the resolution difference between the 645Z and Alpha 1 II?

645Z is 51.4 MP and Alpha 1 II is 50.1 MP, so the 645Z captures more detail for cropping and large prints.

Do the 645Z and Alpha 1 II have in-body image stabilization?

645Z has 7-stop in-body image stabilization, while Alpha 1 II has 8.5-stop in-body image stabilization.

Which shoots faster bursts — the 645Z or the Alpha 1 II?

645Z reaches 20 fps electronic. Alpha 1 II reaches 30 fps electronic.

What's the weight difference between the 645Z and Alpha 1 II?

645Z weighs 1470 g and Alpha 1 II weighs 743 g, so the Alpha 1 II is 727 g lighter.

Do the 645Z and Alpha 1 II record 4K video?

645Z: 4K up to 60p. Alpha 1 II: 8K (max), 4K up to 120p.

Are the 645Z and Alpha 1 II weather sealed?

645Z: Yes. Alpha 1 II: Yes.

Which has better battery life?

Rated battery life is 640 shots (CIPA) for the 645Z and 520 shots for the Alpha 1 II, giving the 645Z the edge.

How much does each cost?

645Z launched at $8,499 and Alpha 1 II at $6,499. The Alpha 1 II is $2,000 less.

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

Add any camera to get a three-way 645Z vs Alpha 1 II vs X comparison.

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

Product images courtesy of Pentax and Sony press materials.