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Pentax

K-1

Original 36MP full-frame Pentax DSLR with 5-axis SR, AA filter simulator, and weather sealing.

$1,799

Launch price

Released Apr 2016

vs
GR IVx

Ricoh

GR IVx

40mm-equivalent GR IV sibling with a newly designed 26.1mm f/2.8 lens, 25.74MP APS-C sensor, 5-axis SR, 4K video, 53GB internal storage, and pocket street-camera handling. Winter 2026 planned.

$1,499

Launch price

Released Dec 2026

GR IVx is 10.6 years newer.

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Wins

7categories

K-1

WildlifePortrait

Wins

2categories

GR IVx

Portrait

2 categories tied

Which would you choose?

TL;DR — Key differences

K-1 wins 3 categories·GR IVx wins 2 categories
  • BGR IVx has higher ISO max (native) (204,800 vs 25,600)
  • AK-1 has higher Burst (electronic) (20 fps vs 4 fps)
  • BGR IVx has lower Weight (265 g vs 1010 g)
  • AK-1 has higher Battery life (CIPA) (640 shots vs 250 shots)
  • AK-1 has higher AF points / zones (101 vs 49)

Key specs at a glance

K-1GR IVx
Resolution36.4 MP25.74 MP
SensorFull FrameAPS-C
ISO max25,600204,800
Burst20 fps4 fps
4K60 fps30 fps
IBIS5-stopYes
Weight1010 g265 g
Battery640 shots250 shots

Size and weight, to scale

K-1

137 × 111 × 87 mm

1010 g (2.23 lb / 35.63 oz)

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

Credit card

85.6 × 54 mm

for scale

GR IVx front view

GR IVx

109 × 61 × 33 mm

265 g (0.58 lb / 9.35 oz)

K-1 is 28mm wider, 49mm taller, and 53mm thicker than GR IVx.

K-1 is 745 g heavier than GR IVx.

Depth (front-to-back): 87mm K-1 · 33mm GR IVx

Sensor size, to scale

K-1

35.9 × 24 mm · Full Frame

862 mm² area

GR IVx

23.3 × 15.5 mm · APS-C

361 mm² area

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

Lens ecosystem

Native lens selection

K-1

✓ more lenses

Pentax K

70+

native lenses available

30 first-party40 third-party

GR IVx: mount data unavailable

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-1GR IVx
Portrait
8.0Excellent✓ wins
6.5Good
Sports & Action
6.5Good✓ wins
1.0Limited
Video & Hybrid
6.0Good✓ wins
4.0Fair
Landscape
7.5Good✓ wins
2.5Limited
Travel
6.5Good✓ wins
5.5Fair
Wildlife
9.0Excellent✓ wins
1.0Limited
Vlogging
5.5Fair
5.5Fair

Why pick one over the other

Reasons to choose

K-1

  • Subject recognition

    Adds Human, Animal, Bird…

  • Codecs

    Adds H.265, H.264

  • Dimensions (W×H×D mm)

    Adds 137, 110.5, 86.5

  • Card types

    Adds SD UHS-II

  • Burst (electronic)

    20 fps vs 4 fps — higher is better

  • Battery life (CIPA)

    640 shots vs 250 shots — higher is better

  • AF points / zones

    101 vs 49 — higher is better

  • AA filter

    Only K-1 supports it

Reasons to choose

GR IVx

  • Subject recognition

    Adds Face, Eye

  • Codecs

    Adds MPEG-4 AVC/H.264, MOV

  • Dimensions (W×H×D mm)

    Adds 109.4, 61.1, 33.4

  • Card types

    Adds microSD, microSDHC, microSDXC UHS-I

  • ISO max (native)

    204,800 vs 25,600 — higher is better

  • Weight

    265 g vs 1010 g — lower is better

Both cameras share

  • ISO min (native)Both 100
  • Eye AFBoth support eye af
  • Max video bit rateBoth 150 Mbps
  • In-body stabilization (IBIS)Both support in-body stabilization (ibis)
  • TouchscreenBoth support touchscreen
  • Wi-FiBoth support wi-fi

Pros & cons at a glance

Editorially curated highlights and trade-offs.

K-1

Pros

  • 36MP full-frame
  • IBIS in DSLR
  • AA filter simulator
  • Weather sealed

Cons

  • Slow AF vs mirrorless
  • Heavy
  • Superseded by K-1 II

GR IVx

Pros

  • New 26.1mm f/2.8 GR lens (40mm equiv.)
  • GR IV 25.74MP APS-C + 5-axis SR
  • 4K 30p/24p and 53GB built-in storage
  • Snap focus, 50/71mm crops, 2-stop ND
  • Pocketable 265g body

Cons

  • Price not yet announced (listed at GR IV $1,499)
  • Winter 2026 or later — still in development as of Aug 2026
  • No built-in EVF
  • Fixed 40mm-equiv. lens

Decided which one is right for you?

Compare live prices for the K-1 and GR IVx at major authorized retailers.

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Full specifications

= category winner

K-1
GR IVx
Resolution
36.4 MP+41%
25.74 MP
Sensor type
Full Frame CMOS
APS-C CMOS
Sensor size
35.9 × 24.0 mm
23.3 x 15.5 mm
AA filter
Yes
No
K-1
GR IVx
Aperture
F2.8-F16
Focal length (35mm equiv.)
40 mm
K-1
GR IVx
Processor
Image processor
GR ENGINE 7
K-1
GR IVx
ISO min (native)
100
100
ISO max (native)
25,600
204,800+3 stops
ISO max (expanded)
102,400
204,800
K-1
GR IVx
Shutter type
Mechanical + Electronic
Leaf shutter
Max mechanical speed
1/8000 sec
1/4000 sec
Max electronic speed
1/16000 sec
1/16000 sec

Frequently asked

Quick answers generated from verified specs.

Which is better for wildlife, K-1 or GR IVx?

K-1 scores 9.0/10 versus 1.0/10 for GR IVx — 20fps burst captures fleeting moments.

What's the resolution difference between the K-1 and GR IVx?

K-1 is 36.4 MP and GR IVx is 25.74 MP, so the K-1 captures more detail for cropping and large prints.

Do the K-1 and GR IVx have in-body image stabilization?

K-1 has 5-stop in-body image stabilization, while GR IVx has in-body image stabilization.

Which shoots faster bursts — the K-1 or the GR IVx?

K-1 reaches 20 fps electronic. GR IVx reaches 4 fps electronic.

What's the weight difference between the K-1 and GR IVx?

K-1 weighs 1010 g and GR IVx weighs 265 g, so the GR IVx is 745 g lighter.

Do the K-1 and GR IVx record 4K video?

K-1: 4K up to 60p. GR IVx: 4K up to 30p.

Are the K-1 and GR IVx weather sealed?

K-1: Yes. GR IVx: No.

Which has better battery life?

Rated battery life is 640 shots (CIPA) for the K-1 and 250 shots for the GR IVx, giving the K-1 the edge.

How much does each cost?

K-1 launched at $1,799 and GR IVx at $1,499. The GR IVx is $300 less.

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

Add any camera to get a three-way K-1 vs GR IVx vs X comparison.

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

Product images courtesy of Pentax and Ricoh press materials.