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Pentax

K-3 Mark III Monochrome

Monochrome-only APS-C DSLR with 25.7MP sensor, IBIS, optical viewfinder, and weather sealing.

$2,199

Launch price

Released Apr 2024

vs

Pentax

K-5 IIs

APS-C flagship without AA filter for maximum sharpness — a cult favorite among Pentax stills shooters.

$1,099

Launch price

Released Sep 2012

K-3 Mark III Monochrome is 11.6 years newer.

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Wins

5categories

K-3 Mark III Monochrome

WildlifePortrait

Wins

2categories

K-5 IIs

WildlifeSports & Action

11 categories tied

Which would you choose?

TL;DR — Key differences

K-3 Mark III Monochrome wins 5 categories·K-5 IIs wins 0 categories
  • AK-3 Mark III Monochrome has higher RAW buffer depth (120 frames vs 60 frames)
  • AK-3 Mark III Monochrome has higher Resolution (25.7 MP vs 16.3 MP)
  • AK-3 Mark III Monochrome has higher EVF resolution (3,690,000 vs 2,360,000)
  • AK-3 Mark III Monochrome has higher Burst (mechanical) (8 fps vs 6 fps)
  • AK-3 Mark III Monochrome has higher Burst (electronic) (20 fps vs 15 fps)

Key specs at a glance

K-3 Mark III MonochromeK-5 IIs
Resolution25.7 MP16.3 MP
SensorAPS-CAPS-C
ISO max25,60025,600
Burst20 fps15 fps
4K60 fps60 fps
IBIS5.5-stop6-stop
Weight820 g710 g
Battery640 shots640 shots

Size and weight, to scale

K-3 Mark III Monochrome

135 × 104 × 74 mm

820 g (1.81 lb / 28.92 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 IIs

131 × 97 × 73 mm

710 g (1.57 lb / 25.04 oz)

K-3 Mark III Monochrome is 4mm wider, 7mm taller, and 1mm thicker than K-5 IIs.

K-3 Mark III Monochrome is 110 g heavier than K-5 IIs.

Depth (front-to-back): 74mm K-3 Mark III Monochrome · 73mm K-5 IIs

Sensor size, to scale

K-3 Mark III Monochrome

23.5 × 15.6 mm · APS-C

367 mm² area

K-5 IIs

23.7 × 15.7 mm · APS-C

372 mm² area

Lens ecosystem

Native lens selection

K-3 Mark III Monochrome

✓ more lenses

Pentax K

70+

native lenses available

30 first-party40 third-party

K-5 IIs

✓ 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 caseK-3 Mark III MonochromeK-5 IIs
Portrait
6.5Good✓ wins
5.5Fair
Sports & Action
6.5Good
6.5Good
Video & Hybrid
6.0Good
6.0Good
Landscape
5.0Fair✓ wins
3.5Limited
Travel
6.5Good
6.5Good
Wildlife
10.0Excellent✓ wins
8.0Excellent
Vlogging
5.5Fair
5.5Fair

Why pick one over the other

Reasons to choose

K-3 Mark III Monochrome

  • Dimensions (W×H×D mm)

    Adds 134.5, 103.5, 73.5

  • RAW buffer depth

    120 frames vs 60 frames — higher is better

  • Resolution

    25.7 MP vs 16.3 MP — higher is better

  • EVF resolution

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

  • Burst (mechanical)

    8 fps vs 6 fps — higher is better

  • Burst (electronic)

    20 fps vs 15 fps — higher is better

Reasons to choose

K-5 IIs

  • Dimensions (W×H×D mm)

    Adds 131, 97, 73

  • Weight

    710 g vs 820 g — lower is better

  • IBIS effectiveness

    6 stops vs 5.5 stops — higher is better

Both cameras share

  • ISO min (native)Both 100
  • 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.

K-3 Mark III Monochrome

Pros

  • Dedicated monochrome sensor
  • Optical viewfinder
  • IBIS in a DSLR
  • Weather sealed

Cons

  • Black-and-white only
  • DSLR platform
  • Limited video

K-5 IIs

Pros

  • No AA filter
  • Weather sealed
  • Excellent build
  • Strong JPEG engine

Cons

  • 16MP dated
  • Slow AF
  • DSLR declining

Decided which one is right for you?

Compare live prices for the K-3 Mark III Monochrome and K-5 IIs at major authorized retailers.

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Full specifications

= category winner

K-3 Mark III Monochrome
K-5 IIs
Resolution
25.7 MP+58%
16.3 MP
Sensor type
Monochrome APS-C CMOS
APS-C CMOS
Sensor size
23.5 × 15.6 mm
23.7 × 15.7 mm
AA filter
No
No
K-3 Mark III Monochrome
K-5 IIs
Processor
Image processor
Image processor
K-3 Mark III Monochrome
K-5 IIs
ISO min (native)
100
100
ISO max (native)
25,600
25,600
ISO max (expanded)
102,400
102,400
K-3 Mark III Monochrome
K-5 IIs
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 wildlife, K-3 Mark III Monochrome or K-5 IIs?

K-3 Mark III Monochrome scores 10.0/10 versus 8.0/10 for K-5 IIs — 20fps burst captures fleeting moments.

What's the resolution difference between the K-3 Mark III Monochrome and K-5 IIs?

K-3 Mark III Monochrome is 25.7 MP and K-5 IIs is 16.3 MP, so the K-3 Mark III Monochrome captures more detail for cropping and large prints.

Do the K-3 Mark III Monochrome and K-5 IIs have in-body image stabilization?

K-3 Mark III Monochrome has 5.5-stop in-body image stabilization, while K-5 IIs has 6-stop in-body image stabilization.

Which shoots faster bursts — the K-3 Mark III Monochrome or the K-5 IIs?

K-3 Mark III Monochrome reaches 20 fps electronic. K-5 IIs reaches 15 fps electronic.

What's the weight difference between the K-3 Mark III Monochrome and K-5 IIs?

K-3 Mark III Monochrome weighs 820 g and K-5 IIs weighs 710 g, so the K-5 IIs is 110 g lighter.

Do the K-3 Mark III Monochrome and K-5 IIs record 4K video?

K-3 Mark III Monochrome: 4K up to 60p. K-5 IIs: 4K up to 60p.

Are the K-3 Mark III Monochrome and K-5 IIs weather sealed?

K-3 Mark III Monochrome: Yes. K-5 IIs: Yes.

Which has better battery life?

Rated battery life is 640 shots (CIPA) for the K-3 Mark III Monochrome and 640 shots for the K-5 IIs, giving the K-5 IIs the edge.

How much does each cost?

K-3 Mark III Monochrome launched at $2,199 and K-5 IIs at $1,099. The K-5 IIs is $1,100 less.

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

Add any camera to get a three-way K-3 Mark III Monochrome vs K-5 IIs vs X comparison.

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