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
Sony
Alpha 7R VI
66.8MP stacked full-frame high-resolution body with 30fps bursts, 8K 30p, 4K 120p, and Sony's AI processing unit.
$4,499
Launch priceReleased Jun 2026
Alpha 7R VI is 2.1 years newer.
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Wins
K-3 Mark III Monochrome
Wins
Alpha 7R VI
2 categories tied
Which would you choose?
TL;DR — Key differences
- BAlpha 7R VI has higher AF points / zones (759 vs 101)
- BAlpha 7R VI has higher Max video bit rate (600 Mbps vs 150 Mbps)
- BAlpha 7R VI has higher Resolution (66.8 MP vs 25.7 MP)
- BAlpha 7R VI has higher EVF resolution (9,437,184 vs 3,690,000)
- BAlpha 7R VI has higher 4K max frame rate (120 fps vs 60 fps)
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
Alpha 7R VI
133 × 97 × 83 mm
713 g (1.57 lb / 25.15 oz)
K-3 Mark III Monochrome is 9mm thinner than Alpha 7R VI but it is also 2mm wider and 7mm taller.
K-3 Mark III Monochrome is 107 g heavier than Alpha 7R VI.
Depth (front-to-back): 74mm K-3 Mark III Monochrome · 83mm Alpha 7R VI
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
Alpha 7R VI
133 × 97 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
Alpha 7R VI
133 × 83 mm
Sensor size, to scale
K-3 Mark III Monochrome
23.5 × 15.6 mm · APS-C
367 mm² area
Alpha 7R VI
35.9 × 24 mm · Full Frame
862 mm² area
2.3× larger sensor area = shallower depth of field and better low-light performance.
Lens ecosystem
Native lens selection
K-3 Mark III Monochrome
Pentax K
70+
native lenses available
Alpha 7R VI
✓ more lensesSony E
350+
native lenses available
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
Dimensions (W×H×D mm)
Adds 134.5, 103.5, 73.5
Card types
Adds SD UHS-II
Pre-Capture / Pre-Release
Only K-3 Mark III Monochrome supports it
Weather sealing
Only K-3 Mark III Monochrome supports it
Battery life (CIPA)
640 shots vs 600 shots — higher is better
Reasons to choose
Alpha 7R VI
AF low-light limit
-6 EV vs -3 EV — lower is better
Dimensions (W×H×D mm)
Adds 132.7, 96.9, 82.9
Card types
Adds CFexpress Type A, SDXC UHS-II
AF points / zones
759 vs 101 — higher is better
Max video bit rate
600 Mbps vs 150 Mbps — higher is better
Resolution
66.8 MP vs 25.7 MP — higher is better
EVF resolution
9,437,184 vs 3,690,000 — higher is better
Codecs
Adds XAVC HS, XAVC S, XAVC S-I
Both cameras share
- ✓ISO min (native) — Both 100
- ✓Eye AF — Both support eye af
- ✓Animal / bird AF — Both support animal / bird af
- ✓In-body stabilization (IBIS) — Both support in-body stabilization (ibis)
- ✓Card slots — Both 2
- ✓Touchscreen — Both support touchscreen
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
Alpha 7R VI
Pros
- ✓66.8MP stacked full-frame sensor
- ✓30fps blackout-free electronic burst
- ✓8K 30p and 4K 120p video
- ✓5-axis sensor-shift stabilization
- ✓9.44M-dot HDR OLED EVF
Cons
- –Very expensive
- –Large files demand fast cards and storage
- –8K workflow can be heavy
Decided which one is right for you?
Compare live prices for the K-3 Mark III Monochrome and Alpha 7R VI at major authorized retailers.
Pentax K-3 Mark III Monochrome
Sony Alpha 7R VI
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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 Alpha 7R VI?
K-3 Mark III Monochrome scores 10.0/10 versus 6.5/10 for Alpha 7R VI — 20fps burst captures fleeting moments.
What's the resolution difference between the K-3 Mark III Monochrome and Alpha 7R VI?
K-3 Mark III Monochrome is 25.7 MP and Alpha 7R VI is 66.8 MP, so the Alpha 7R VI captures more detail for cropping and large prints.
Do the K-3 Mark III Monochrome and Alpha 7R VI have in-body image stabilization?
K-3 Mark III Monochrome has 5.5-stop in-body image stabilization, while Alpha 7R VI has in-body image stabilization.
Which shoots faster bursts — the K-3 Mark III Monochrome or the Alpha 7R VI?
K-3 Mark III Monochrome reaches 20 fps electronic. Alpha 7R VI reaches 30 fps electronic.
What's the weight difference between the K-3 Mark III Monochrome and Alpha 7R VI?
K-3 Mark III Monochrome weighs 820 g and Alpha 7R VI weighs 713 g, so the Alpha 7R VI is 107 g lighter.
Do the K-3 Mark III Monochrome and Alpha 7R VI record 4K video?
K-3 Mark III Monochrome: 4K up to 60p. Alpha 7R VI: 8K (max), 4K up to 120p.
Are the K-3 Mark III Monochrome and Alpha 7R VI weather sealed?
K-3 Mark III Monochrome: Yes. Alpha 7R VI: No.
Which has better battery life?
Rated battery life is 640 shots (CIPA) for the K-3 Mark III Monochrome and 600 shots for the Alpha 7R VI, giving the K-3 Mark III Monochrome the edge.
How much does each cost?
K-3 Mark III Monochrome launched at $2,199 and Alpha 7R VI at $4,499. The K-3 Mark III Monochrome is $2,300 less.
Can't decide between two? Compare a third camera.
Add any camera to get a three-way K-3 Mark III Monochrome vs Alpha 7R VI vs X comparison.
Specs sourced from manufacturer data. Use-case scores algorithmically derived. Last reviewed June 2026.
Product images courtesy of Pentax and Sony press materials.