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Pentax K-3 Mark III

Real Sensor Data

Brand
Pentax
Sensor Format
APS-C (1.5x)
Resolution
25.7 MP
Pixel Pitch
3.78 microns
Circle of Confusion
0.0188 mm
Crop Factor
1.53x
Announced
2021

Released in 2021, the K-3 Mark III is a genuine APS-C DSLR built with an optical viewfinder rather than an electronic one, a design choice Pentax has continued to commit to well after most other manufacturers shifted their new development entirely to mirrorless — a real, deliberate holdout for photographers who specifically prefer an optical viewfinder's zero-lag, direct view.

Pentax K-3 Mark III sensor specs

Sensor
APS-C (1.5x)
Resolution
25.7 MP
Pixel dimensions
6,209 × 4,139 px
Aspect ratio
3:2
Pixel pitch
3.78 µm
Crop factor
1.53x
Circle of confusion
0.0188 mm

APS-C sensor · DoF & Hyperfocal Calculator · Astro 500/NPF Calculator

The K-3 Mark III also introduced a newly designed, notably bright optical viewfinder with close to 100% frame coverage, a genuine engineering investment in traditional DSLR viewing quality at a time when most manufacturers had shifted that same investment toward electronic viewfinders instead. A genuine commitment to the optical-viewfinder shooting experience Pentax's core audience specifically values. A meaningfully brighter view than earlier K-3 generations offered.

Pentax also gave the K-3 Mark III a genuinely rugged magnesium-alloy body rated for extensive weather sealing, construction quality matching its positioning as Pentax's flagship APS-C DSLR.

See these numbers used live in the DoF & Hyperfocal Calculator by selecting the APS-C (1.5x) sensor format.

Frequently Asked Questions

Why does Pentax still make DSLRs when most other brands have moved to mirrorless?

Pentax has deliberately continued DSLR development for photographers who specifically prefer an optical viewfinder's direct, lag-free view and DSLR ergonomics, along with strong backward compatibility with decades of existing Pentax K-mount lenses — a genuine, sustained market niche rather than an oversight or lag in product development.