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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

Pentax

K-5

Legendary weather-sealed APS-C DSLR with 16MP sensor and exceptional build quality.

$1,099

Launch price

Released Sep 2010

645Z is 3.6 years newer.

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Wins

7categories

645Z

WildlifeLandscape

Wins

1categories

K-5

WildlifeSports & Action

10 categories tied

Which would you choose?

TL;DR — Key differences

645Z wins 4 categories·K-5 wins 1 categories
  • A645Z has higher Resolution (51.4 MP vs 16.3 MP)
  • A645Z has higher RAW buffer depth (120 frames vs 60 frames)
  • BK-5 has lower Weight (750 g vs 1470 g)
  • A645Z has higher EVF resolution (3,690,000 vs 2,360,000)
  • A645Z has lower ISO min (native) (64 vs 100)

Key specs at a glance

645ZK-5
Resolution51.4 MP16.3 MP
Sensor43.8 × 32.8 mmAPS-C
ISO max25,60025,600
Burst20 fps15 fps
4K60 fps60 fps
IBIS7-stop6-stop
Weight1470 g750 g
Battery640 shots640 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

K-5

131 × 97 × 73 mm

750 g (1.65 lb / 26.46 oz)

645Z is 25mm wider, 20mm taller, and 50mm thicker than K-5.

645Z is 720 g heavier than K-5.

Depth (front-to-back): 123mm 645Z · 73mm K-5

Sensor size, to scale

645Z

43.8 × 32.8 mm · Medium Format

1437 mm² area

K-5

23.7 × 15.7 mm · APS-C

372 mm² area

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

Lens ecosystem

Native lens selection

645Z: mount data unavailable

K-5

✓ more lenses

Pentax K

70+

native lenses available

30 first-party40 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 case645ZK-5
Portrait
6.0Good✓ wins
5.5Fair
Sports & Action
6.5Good
6.5Good
Video & Hybrid
6.0Good
6.0Good
Landscape
8.0Excellent✓ wins
3.5Limited
Travel
5.5Fair
6.5Good✓ wins
Wildlife
9.0Excellent✓ wins
8.0Excellent
Vlogging
5.5Fair
5.5Fair

Why pick one over the other

Reasons to choose

645Z

  • Dimensions (W×H×D mm)

    Adds 156, 117, 123

  • Resolution

    51.4 MP vs 16.3 MP — higher is better

  • RAW buffer depth

    120 frames vs 60 frames — higher is better

  • EVF resolution

    3,690,000 vs 2,360,000 — higher is better

  • ISO min (native)

    64 vs 100 — lower is better

  • Burst (mechanical)

    8 fps vs 6 fps — higher is better

  • Burst (electronic)

    20 fps vs 15 fps — higher is better

  • IBIS effectiveness

    7 stops vs 6 stops — higher is better

Reasons to choose

K-5

  • Dimensions (W×H×D mm)

    Adds 131, 97, 73

  • Weight

    750 g vs 1470 g — lower is better

Both cameras share

  • AA filterBoth support aa filter
  • ISO max (native)Both 25,600
  • AF points / zonesBoth 101
  • AF frame coverageBoth 100 %
  • Eye AFBoth support eye af
  • Animal / bird AFBoth support animal / bird af

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

K-5

Pros

  • Legendary build
  • Weather sealed
  • Excellent JPEG engine
  • Compact pro DSLR

Cons

  • 16MP very dated
  • Slow AF
  • DSLR niche

Decided which one is right for you?

Compare live prices for the 645Z and K-5 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

645Z
K-5
Resolution
51.4 MP3.2× more
16.3 MP
Sensor type
Medium Format CMOS
APS-C CMOS
Sensor size
43.8 × 32.8 mm
23.7 × 15.7 mm
AA filter
Yes
Yes
645Z
K-5
Processor
Image processor
Image processor
645Z
K-5
ISO min (native)
64−36 less
100
ISO max (native)
25,600
25,600
ISO max (expanded)
102,400
102,400
645Z
K-5
Shutter type
Mechanical + Electronic
Mechanical + Electronic
Max mechanical speed
1/8000 sec
1/8000 sec
Max electronic speed
1/16000 sec
1/16000 sec

Frequently asked

Quick answers generated from verified specs.

Which is better for landscape, 645Z or K-5?

645Z scores 8.0/10 versus 3.5/10 for K-5 — 51.4MP — massive detail for large prints.

What's the resolution difference between the 645Z and K-5?

645Z is 51.4 MP and K-5 is 16.3 MP, so the 645Z captures more detail for cropping and large prints.

Do the 645Z and K-5 have in-body image stabilization?

645Z has 7-stop in-body image stabilization, while K-5 has 6-stop in-body image stabilization.

Which shoots faster bursts — the 645Z or the K-5?

645Z reaches 20 fps electronic. K-5 reaches 15 fps electronic.

What's the weight difference between the 645Z and K-5?

645Z weighs 1470 g and K-5 weighs 750 g, so the K-5 is 720 g lighter.

Do the 645Z and K-5 record 4K video?

645Z: 4K up to 60p. K-5: 4K up to 60p.

Are the 645Z and K-5 weather sealed?

645Z: Yes. K-5: Yes.

Which has better battery life?

Rated battery life is 640 shots (CIPA) for the 645Z and 640 shots for the K-5, giving the K-5 the edge.

How much does each cost?

645Z launched at $8,499 and K-5 at $1,099. The K-5 is $7,400 less.

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

Add any camera to get a three-way 645Z vs K-5 vs X comparison.

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