Pentax
645Z
51MP medium format DSLR that made digital MF accessible — still prized for landscape and studio.
$8,499
Launch priceReleased Apr 2014
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 12.1 years newer.
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Wins
645Z
Wins
Alpha 7R VI
1 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 EVF resolution (9,437,184 vs 3,690,000)
- BAlpha 7R VI has lower Weight (713 g vs 1470 g)
- 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 share645Z
156 × 117 × 123 mm
1470 g (3.24 lb / 51.85 oz)
Credit card
85.6 × 54 mm
for scale
Alpha 7R VI
133 × 97 × 83 mm
713 g (1.57 lb / 25.15 oz)
645Z is 23mm wider, 20mm taller, and 40mm thicker than Alpha 7R VI.
645Z is 757 g heavier than Alpha 7R VI.
Depth (front-to-back): 123mm 645Z · 83mm Alpha 7R VI
Back view, to scale
Width × Height — same proportions as the front of the body.
645Z
156 × 117 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.
645Z
156 × 123 mm
Credit card
85.6 × 54 mm
Alpha 7R VI
133 × 83 mm
Sensor size, to scale
645Z
43.8 × 32.8 mm · Medium Format
1437 mm² area
Alpha 7R VI
35.9 × 24 mm · Full Frame
862 mm² area
1.7× larger sensor area = shallower depth of field and better low-light performance.
Lens ecosystem
Native lens selection
645Z: mount data unavailable
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
645Z
Dimensions (W×H×D mm)
Adds 156, 117, 123
Card types
Adds SD UHS-II
AA filter
Only 645Z supports it
Pre-Capture / Pre-Release
Only 645Z supports it
Weather sealing
Only 645Z supports it
ISO min (native)
64 vs 100 — lower is better
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
EVF resolution
9,437,184 vs 3,690,000 — higher is better
Codecs
Adds XAVC HS, XAVC S, XAVC S-I
Weight
713 g vs 1470 g — lower is better
Both cameras share
- ✓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
- ✓Wi-Fi — Both support wi-fi
Pros & cons at a glance
Editorially curated highlights and trade-offs.
645Z
Pros
- ✓51MP medium format
- ✓CMOS sensor
- ✓Pentax color
- ✓Relatively affordable MF
Cons
- –Huge body
- –Slow operation
- –Limited lens line vs Hasselblad
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 645Z and Alpha 7R VI at major authorized retailers.
Pentax 645Z
Sony Alpha 7R VI
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Full specifications
✓ = category winner
Frequently asked
Quick answers generated from verified specs.
Which is better for portraits, 645Z or Alpha 7R VI?
Alpha 7R VI scores 8.5/10 versus 6.0/10 for 645Z — 66.8MP — excellent for large prints and crops.
What's the resolution difference between the 645Z and Alpha 7R VI?
645Z is 51.4 MP and Alpha 7R VI is 66.8 MP, so the Alpha 7R VI captures more detail for cropping and large prints.
Do the 645Z and Alpha 7R VI have in-body image stabilization?
645Z has 7-stop in-body image stabilization, while Alpha 7R VI has in-body image stabilization.
Which shoots faster bursts — the 645Z or the Alpha 7R VI?
645Z reaches 20 fps electronic. Alpha 7R VI reaches 30 fps electronic.
What's the weight difference between the 645Z and Alpha 7R VI?
645Z weighs 1470 g and Alpha 7R VI weighs 713 g, so the Alpha 7R VI is 757 g lighter.
Do the 645Z and Alpha 7R VI record 4K video?
645Z: 4K up to 60p. Alpha 7R VI: 8K (max), 4K up to 120p.
Are the 645Z and Alpha 7R VI weather sealed?
645Z: Yes. Alpha 7R VI: No.
Which has better battery life?
Rated battery life is 640 shots (CIPA) for the 645Z and 600 shots for the Alpha 7R VI, giving the 645Z the edge.
How much does each cost?
645Z launched at $8,499 and Alpha 7R VI at $4,499. The Alpha 7R VI is $4,000 less.
Can't decide between two? Compare a third camera.
Add any camera to get a three-way 645Z 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.