Pentax
K-3 Mark III Monochrome
Monochrome-only APS-C DSLR with 25.7MP sensor, IBIS, optical viewfinder, and weather sealing.
$2,199
Launch priceReleased Apr 2024
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
Launch priceReleased Jan 2026
GR IV is 1.7 years newer.
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Wins
K-3 Mark III Monochrome
Wins
GR IV
2 categories tied
Which would you choose?
TL;DR — Key differences
- BGR IV has higher ISO max (native) (204,800 vs 25,600)
- AK-3 Mark III Monochrome has higher Burst (electronic) (20 fps vs 4 fps)
- BGR IV has lower Weight (262 g vs 820 g)
- AK-3 Mark III Monochrome has higher Battery life (CIPA) (640 shots vs 250 shots)
- AK-3 Mark III Monochrome has higher AF points / zones (101 vs 49)
Key specs at a glance
Size and weight, to scale
📸 Snap this size diff to shareK-3 Mark III Monochrome
135 × 104 × 74 mm
820 g (1.81 lb / 28.92 oz)
Credit card
85.6 × 54 mm
for scale
GR IV
109 × 61 × 33 mm
262 g (0.58 lb / 9.24 oz)
K-3 Mark III Monochrome is 25mm wider, 42mm taller, and 41mm thicker than GR IV.
K-3 Mark III Monochrome is 558 g heavier than GR IV.
Depth (front-to-back): 74mm K-3 Mark III Monochrome · 33mm GR IV
Back view, to scale
Width × Height — same proportions as the front of the body.
K-3 Mark III Monochrome
135 × 104 mm
Credit card
85.6 × 54 mm
GR IV
109 × 61 mm
Top view, to scale
Width × Depth (front-to-back) — see which body is chunkier on the table.
K-3 Mark III Monochrome
135 × 74 mm
Credit card
85.6 × 54 mm
GR IV
109 × 33 mm
Sensor size, to scale
K-3 Mark III Monochrome
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 Monochrome
✓ 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 Monochrome
Subject recognition
Adds Human, Animal, Bird…
Codecs
Adds H.265, H.264
Dimensions (W×H×D mm)
Adds 134.5, 103.5, 73.5
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
Animal / bird AF
Only K-3 Mark III Monochrome 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 820 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 (IBIS) — Both support in-body stabilization (ibis)
- ✓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 Monochrome
Pros
- ✓Dedicated monochrome sensor
- ✓Optical viewfinder
- ✓IBIS in a DSLR
- ✓Weather sealed
Cons
- –Black-and-white only
- –DSLR platform
- –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
Decided which one is right for you?
Compare live prices for the K-3 Mark III Monochrome and GR IV at major authorized retailers.
Pentax K-3 Mark III Monochrome
Ricoh GR IV
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Full specifications
✓ = category winner
Frequently asked
Quick answers generated from verified specs.
Which is better for wildlife, K-3 Mark III Monochrome or GR IV?
K-3 Mark III Monochrome 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 Monochrome and GR IV?
K-3 Mark III Monochrome 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 Monochrome and GR IV have in-body image stabilization?
K-3 Mark III Monochrome has 5.5-stop in-body image stabilization, while GR IV has in-body image stabilization.
Which shoots faster bursts — the K-3 Mark III Monochrome or the GR IV?
K-3 Mark III Monochrome reaches 20 fps electronic. GR IV reaches 4 fps electronic.
What's the weight difference between the K-3 Mark III Monochrome and GR IV?
K-3 Mark III Monochrome weighs 820 g and GR IV weighs 262 g, so the GR IV is 558 g lighter.
Do the K-3 Mark III Monochrome and GR IV record 4K video?
K-3 Mark III Monochrome: 4K up to 60p. GR IV: 4K up to 60p.
Are the K-3 Mark III Monochrome and GR IV weather sealed?
K-3 Mark III Monochrome: Yes. GR IV: No.
Which has better battery life?
Rated battery life is 640 shots (CIPA) for the K-3 Mark III Monochrome and 250 shots for the GR IV, giving the K-3 Mark III Monochrome the edge.
How much does each cost?
K-3 Mark III Monochrome launched at $2,199 and GR IV at $1,499. The GR IV is $700 less.
Can't decide between two? Compare a third camera.
Add any camera to get a three-way K-3 Mark III Monochrome vs GR IV vs X comparison.
Specs sourced from manufacturer data. Use-case scores algorithmically derived. Last reviewed June 2026.
Product images courtesy of Pentax and Ricoh press materials.