Pentax
K-3 Mark III
APS-C DSLR flagship with optical viewfinder and weather sealing.
$1,999
Launch priceReleased Apr 2021
Pentax
K-S2
Compact weather-sealed APS-C DSLR with 20MP sensor, AA filter simulator, and built-in Wi-Fi.
$799
Launch priceReleased Feb 2015
K-3 Mark III is 6.2 years newer.
Affiliate disclosure: As an Amazon Associate, Cameraegg earns from qualifying purchases. Cameraegg may also earn commission from B&H links, at no extra cost to you.
Wins
K-3 Mark III
Wins
K-S2
11 categories tied
Which would you choose?
TL;DR — Key differences
- AK-3 Mark III has higher RAW buffer depth (120 frames vs 60 frames)
- AK-3 Mark III has higher EVF resolution (3,690,000 vs 2,360,000)
- AK-3 Mark III has higher Burst (mechanical) (8 fps vs 6 fps)
- AK-3 Mark III has higher Burst (electronic) (20 fps vs 15 fps)
- AK-3 Mark III has lower Weight (520 g vs 678 g)
Key specs at a glance
Size and weight, to scale
📸 Snap this size diff to shareK-3 Mark III
138 × 98 × 88 mm
520 g (1.15 lb / 18.34 oz)
Credit card
85.6 × 54 mm
for scale
K-S2
123 × 91 × 77 mm
678 g (1.49 lb / 23.92 oz)
K-3 Mark III is 16mm wider, 7mm taller, and 11mm thicker than K-S2.
K-3 Mark III is 158 g lighter than K-S2.
Depth (front-to-back): 88mm K-3 Mark III · 77mm K-S2
Sensor size, to scale
K-3 Mark III
23.5 × 15.6 mm · APS-C
367 mm² area
K-S2
23.5 × 15.6 mm · APS-C
367 mm² area
Lens ecosystem
Native lens selection
K-3 Mark III
✓ more lensesPentax K
70+
native lenses available
K-S2
✓ more lensesPentax K
70+
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
Dimensions (W×H×D mm)
Adds 138, 98, 88
RAW buffer depth
120 frames vs 60 frames — higher is better
EVF resolution
3,690,000 vs 2,360,000 — higher is better
Burst (mechanical)
8 fps vs 6 fps — higher is better
Burst (electronic)
20 fps vs 15 fps — higher is better
Weight
520 g vs 678 g — lower is better
Resolution
25.7 MP vs 20.1 MP — higher is better
IBIS effectiveness
7 stops vs 6 stops — higher is better
Reasons to choose
K-S2
Dimensions (W×H×D mm)
Adds 122.5, 91.4, 76.9
AA filter
Only K-S2 supports it
Both cameras share
- ✓ISO min (native) — Both 100
- ✓ISO max (native) — Both 25,600
- ✓AF points / zones — Both 101
- ✓AF frame coverage — Both 100 %
- ✓Eye AF — Both support eye af
- ✓Animal / bird AF — Both support animal / bird af
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
K-S2
Pros
- ✓Weather sealed
- ✓Compact DSLR
- ✓AA filter simulator
- ✓Wi-Fi
Cons
- –20MP dated
- –No IBIS
- –DSLR niche
Decided which one is right for you?
Compare live prices for the K-3 Mark III and K-S2 at major authorized retailers.
Pentax K-3 Mark III
Pentax K-S2
Affiliate disclosure: As an Amazon Associate, Cameraegg earns from qualifying purchases. Cameraegg may also earn commission from B&H links, at no extra cost to you.
Full specifications
✓ = category winner
Frequently asked
Quick answers generated from verified specs.
Which is better for travel, K-3 Mark III or K-S2?
K-3 Mark III scores 8.5/10 versus 6.5/10 for K-S2 — 520g — compact and travel-friendly.
What's the resolution difference between the K-3 Mark III and K-S2?
K-3 Mark III is 25.7 MP and K-S2 is 20.1 MP, so the K-3 Mark III captures more detail for cropping and large prints.
Do the K-3 Mark III and K-S2 have in-body image stabilization?
K-3 Mark III has 7-stop in-body image stabilization, while K-S2 has 6-stop in-body image stabilization.
Which shoots faster bursts — the K-3 Mark III or the K-S2?
K-3 Mark III reaches 20 fps electronic. K-S2 reaches 15 fps electronic.
What's the weight difference between the K-3 Mark III and K-S2?
K-3 Mark III weighs 520 g and K-S2 weighs 678 g, so the K-3 Mark III is 158 g lighter.
Do the K-3 Mark III and K-S2 record 4K video?
K-3 Mark III: 4K up to 60p. K-S2: 4K up to 60p.
Are the K-3 Mark III and K-S2 weather sealed?
K-3 Mark III: Yes. K-S2: Yes.
Which has better battery life?
Rated battery life is 640 shots (CIPA) for the K-3 Mark III and 640 shots for the K-S2, giving the K-S2 the edge.
How much does each cost?
K-3 Mark III launched at $1,999 and K-S2 at $799. The K-S2 is $1,200 less.
Can't decide between two? Compare a third camera.
Add any camera to get a three-way K-3 Mark III vs K-S2 vs X comparison.
Specs sourced from manufacturer data. Use-case scores algorithmically derived. Last reviewed June 2026.