Reasons to choose K-3 Mark III
Released in 2021, K-3 Mark III has about 361 mm² of sensor area, 25.73 MP effective resolution, and a 820 g body. Use these values to narrow the field, not as an overall image-quality score.
Side-by-side comparison
Pentax K-3 Mark III
vs Ricoh GR IIIx
VS
Sensor area
361 mm²
K-3 Mark III367 mm²
GR IIIx- Area ratio
- 1.02:1
- Absolute difference
- 5 mm²
- Relative difference
- 1.5%
The GR IIIx has the larger sensor area. More area usually means greater light-gathering potential, though real image quality still depends on sensor architecture and generation.
Key specification differences
K-3 Mark IIIMetricGR IIIx
25.73 MPEffective pixels24.24 MP
23.3 × 15.5Sensor23.5 × 15.6
3.75 µmPixel pitch3.89 µm
14.04 µm²Pixel area15.12 µm²
7.12 MP/cm²Pixel density6.61 MP/cm²
1.55Crop factor1.53
3,840 × 2,160Maximum video1,920 × 1,080
820 gWeight262 g
SD/SDHC/SDXCStorageSD/SDHC/SDXC
D-LI90 Lithium-ion battery Li-ion batteryBatteryDB-110 lithium-ion battery Li-ion battery
Amber marks the value that is generally preferable in this comparison context. It is not an overall camera score.
How to choose between these cameras
The GR IIIx has the larger sensor area. The GR IIIx has the lighter body. The K-3 Mark III has the higher effective resolution. The K-3 Mark III and GR IIIx were both released in 2021. Also consider the lens system and subjects you shoot.
Reasons to choose GR IIIx
Released in 2021, GR IIIx has about 367 mm² of sensor area, 24.24 MP effective resolution, and a 262 g body. Use these values to narrow the field, not as an overall image-quality score.