Pentax
K-3 Mark III
APS-C DSLR flagship with optical viewfinder and weather sealing.
$1,999
Released Apr 2021
Ricoh
GR IV
Latest GR with 25.74MP APS-C sensor, 28mm equivalent lens, 5-axis SR, 53GB internal memory, and pocket street-camera handling.
$1,499
Released Jan 2026
GR IV is 4.7 years newer.
Wins
K-3 Mark III
Wins
GR IV
2 categories tied
TL;DR — Key differences
- BGR IV has higher ISO max (native) (204,800 vs 25,600)
- AK-3 Mark III has higher Burst (electronic) (20 fps vs 4 fps)
- AK-3 Mark III has higher Battery life (CIPA) (640 shots vs 250 shots)
- AK-3 Mark III has higher AF points / zones (101 vs 49)
- AK-3 Mark III has higher Burst (mechanical) (8 fps vs 4 fps)
Key specs at a glance
Size and weight, to scale
K-3 Mark III
138 × 98 × 88 mm
520 g (1.15 lb / 18.34 oz)
GR IV
109 × 61 × 33 mm
262 g (0.58 lb / 9.24 oz)
K-3 Mark III is 29mm wider, 37mm taller, and 55mm thicker than GR IV.
K-3 Mark III is 258 g heavier than GR IV.
Depth (front-to-back): 88mm K-3 Mark III · 33mm GR IV
Sensor size, to scale
K-3 Mark III
23.5 × 15.6 mm · APS-C
367 mm² area
GR IV
23.3 × 15.5 mm · APS-C
361 mm² area
Lens ecosystem
Native lens selection
K-3 Mark III
✓ more lensesPentax K
70+
native lenses available
GR IV: 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
Why pick one over the other
Reasons to choose
K-3 Mark III
Subject recognition
Adds Human, Animal, Bird…
Codecs
Adds H.265, H.264
Dimensions (W×H×D mm)
Adds 138, 98, 88
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
Animal / bird AF
Only K-3 Mark III supports it
Reasons to choose
GR IV
Subject recognition
Adds Face, Eye
Codecs
Adds MPEG-4 AVC/H.264, MOV
Dimensions (W×H×D mm)
Adds 109.4, 61.1, 32.7
Card types
Adds microSD, microSDHC, microSDXC UHS-I
ISO max (native)
204,800 vs 25,600 — higher is better
Weight
262 g vs 520 g — lower is better
Resolution
25.74 MP vs 25.7 MP — higher is better
Both cameras share
- ✓ISO min (native) — Both 100
- ✓Eye AF — Both support eye af
- ✓4K max frame rate — Both 60 fps
- ✓In-body stabilization — Both support in-body stabilization
- ✓Touchscreen — Both support touchscreen
- ✓Wi-Fi — Both support wi-fi
Pros & cons at a glance
Editorially curated highlights and trade-offs.
K-3 Mark III
Pros
- ✓Optical viewfinder
- ✓Weather sealed
- ✓IBIS in DSLR
Cons
- –DSLR system declining
- –APS-C
- –Limited video
GR IV
Pros
- ✓25.74MP APS-C sensor
- ✓5-axis sensor-shift SR
- ✓53GB internal memory
- ✓Pocketable 28mm GR lens
Cons
- –Fixed lens
- –No built-in EVF
- –Full HD video only
Full specifications
✓ = category winner
Frequently asked
Quick answers generated from verified specs.
Which is better for wildlife, K-3 Mark III or GR IV?
K-3 Mark III scores 10.0/10 versus 1.0/10 for GR IV — 20fps burst captures fleeting moments.
What's the resolution difference between the K-3 Mark III and GR IV?
K-3 Mark III is 25.7 MP and GR IV is 25.74 MP, so the GR IV captures more detail for cropping and large prints.
Do the K-3 Mark III and GR IV have in-body image stabilization?
K-3 Mark III has 7-stop in-body image stabilization, while gR IV has in-body image stabilization.
Which shoots faster bursts — the K-3 Mark III or the GR IV?
K-3 Mark III reaches 20 fps electronic. GR IV reaches 4 fps electronic.
What's the weight difference between the K-3 Mark III and GR IV?
K-3 Mark III weighs 520 g and GR IV weighs 262 g, so the GR IV is 258 g lighter.
Do the K-3 Mark III and GR IV record 4K video?
K-3 Mark III: 4K up to 60p. GR IV: 4K up to 60p.
Are the K-3 Mark III and GR IV weather sealed?
K-3 Mark III: Yes. GR IV: No.
Which has better battery life?
Rated battery life is 640 shots (CIPA) for the K-3 Mark III and 250 shots for the GR IV, giving the K-3 Mark III the edge.
How much does each cost?
K-3 Mark III launched at $1,999 and GR IV at $1,499. The GR IV is $500 less.
Specs sourced from manufacturer data. Use-case scores algorithmically derived. Last reviewed May 2026.