Specifications#
- Brand
- Pentax
- Model
- K-3 III Monochrome
- Also known as
- Pentax K-3 Mark III Monochrome
- Camera type
- DSLR
- Lens mount
- Pentax K
- Sensor size
- 23.3 × 15.5 mm (APS-C)
- Crop factor
- 1.55×
Specifications merged from Lensfun. Spot an error? Tell us.
Sensor size compared#
Focal length equivalents & field of view#
Multiply any focal length by 1.55 to get the full-frame field of view. Angles are for a rectilinear lens focused at infinity.
| Lens on this camera | Full-frame equivalent | Horizontal | Vertical | Diagonal |
|---|---|---|---|---|
| 8 mm | 12 mm | 111.0° | 88.3° | 120.5° |
| 10 mm | 15 mm | 98.7° | 75.6° | 108.9° |
| 12 mm | 19 mm | 88.3° | 65.8° | 98.8° |
| 14 mm | 22 mm | 79.5° | 58.0° | 90.0° |
| 16 mm | 25 mm | 72.1° | 51.7° | 82.3° |
| 18 mm | 28 mm | 65.8° | 46.6° | 75.7° |
| 20 mm | 31 mm | 60.4° | 42.4° | 70.0° |
| 24 mm | 37 mm | 51.8° | 35.8° | 60.5° |
| 28 mm | 43 mm | 45.2° | 31.0° | 53.1° |
| 35 mm | 54 mm | 36.8° | 25.0° | 43.6° |
| 40 mm | 62 mm | 32.5° | 22.0° | 38.6° |
| 50 mm | 77 mm | 26.2° | 17.6° | 31.3° |
| 56 mm | 87 mm | 23.5° | 15.8° | 28.1° |
| 70 mm | 108 mm | 18.9° | 12.7° | 22.6° |
| 85 mm | 131 mm | 15.6° | 10.4° | 18.7° |
| 100 mm | 155 mm | 13.3° | 8.9° | 15.9° |
| 135 mm | 209 mm | 9.9° | 6.6° | 11.8° |
| 200 mm | 309 mm | 6.7° | 4.4° | 8.0° |
| 300 mm | 464 mm | 4.4° | 3.0° | 5.3° |
| 400 mm | 618 mm | 3.3° | 2.2° | 4.0° |
| 600 mm | 928 mm | 2.2° | 1.5° | 2.7° |
| 800 mm | 1237 mm | 1.7° | 1.1° | 2.0° |
Depth of field table#
Total depth of field at each subject distance, using a circle of confusion of 19.4 µm (the 0.030 mm full-frame standard scaled by the crop factor). Detailed tables: 24 mm f/1.8, 24 mm f/2.8, 35 mm f/1.8, 35 mm f/2.8, 50 mm f/1.8, 50 mm f/2.8.
| Focal | Aperture | 50.0 cm | 1.00 m | 2.00 m | 3.00 m | 5.00 m | 10.0 m | Hyperfocal |
|---|---|---|---|---|---|---|---|---|
| 14 mm | f/1.8 | 8.7 cm | 36.3 cm | 1.62 m | 4.45 m | 42.2 m | ∞ | 5.63 m |
| 14 mm | f/2.8 | 13.7 cm | 59.1 cm | 3.16 m | 15.8 m | ∞ | ∞ | 3.62 m |
| 14 mm | f/4 | 20.0 cm | 92.1 cm | 8.25 m | ∞ | ∞ | ∞ | 2.54 m |
| 14 mm | f/8 | 45.2 cm | 4.00 m | ∞ | ∞ | ∞ | ∞ | 1.28 m |
| 28 mm | f/1.8 | 2.1 cm | 8.7 cm | 35.4 cm | 80.9 cm | 2.33 m | 11.1 m | 22.5 m |
| 28 mm | f/2.8 | 3.3 cm | 13.5 cm | 55.7 cm | 1.29 m | 3.91 m | 26.5 m | 14.5 m |
| 28 mm | f/4 | 4.7 cm | 19.4 cm | 81.2 cm | 1.93 m | 6.50 m | 783 m | 10.1 m |
| 28 mm | f/8 | 9.4 cm | 40.0 cm | 1.84 m | 5.40 m | 321 m | ∞ | 5.08 m |
| 48 mm | f/1.8 | 0.7 cm | 2.9 cm | 11.8 cm | 26.9 cm | 75.5 cm | 3.09 m | 66.0 m |
| 48 mm | f/2.8 | 1.1 cm | 4.5 cm | 18.5 cm | 42.0 cm | 1.18 m | 4.97 m | 42.5 m |
| 48 mm | f/4 | 1.5 cm | 6.4 cm | 26.4 cm | 60.3 cm | 1.72 m | 7.56 m | 29.7 m |
| 48 mm | f/8 | 3.0 cm | 12.9 cm | 53.5 cm | 1.24 m | 3.75 m | 24.4 m | 14.9 m |
| 78 mm | f/1.8 | 0.2 cm | 1.1 cm | 4.4 cm | 10.1 cm | 28.3 cm | 1.14 m | 174 m |
| 78 mm | f/2.8 | 0.4 cm | 1.6 cm | 6.9 cm | 15.7 cm | 44.0 cm | 1.79 m | 112 m |
| 78 mm | f/4 | 0.5 cm | 2.4 cm | 9.8 cm | 22.4 cm | 63.0 cm | 2.57 m | 78.5 m |
| 78 mm | f/8 | 1.1 cm | 4.7 cm | 19.7 cm | 45.0 cm | 1.28 m | 5.41 m | 39.3 m |
Equivalent aperture#
Exposure is identical at the same f-number on any format; equivalence only describes depth of field and total light.
Night-sky exposure limits#
Longest exposure before stars trail. The NPF rule accounts for pixel pitch and is stricter than the classic 500 rule — use it for pin-sharp stars on high-resolution sensors. (NPF needs a known resolution and is omitted here.)
| Focal length | 500 rule |
|---|---|
| 9 mm (14 mm eq.) | 35.9 s |
| 13 mm (20 mm eq.) | 24.9 s |
| 16 mm (25 mm eq.) | 20.2 s |
| 23 mm (36 mm eq.) | 14.1 s |
| 32 mm (49 mm eq.) | 10.1 s |
Handheld shutter speed guide#
The reciprocal rule uses the equivalent focal length. High-resolution sensors may need one stop faster than this for pixel-sharp results.
| Focal length | No stabilisation (1/equiv. focal) | With 3-stop IS | With 5-stop IBIS |
|---|---|---|---|
| 16 mm | 1/25 s | 0.3 s | 1.3 s |
| 32 mm | 1/50 s | 1/6 s | 0.6 s |
| 65 mm | 1/100 s | 1/13 s | 0.3 s |
| 129 mm | 1/200 s | 1/25 s | 1/6 s |
Lenses for the Pentax K-3 III Monochrome#
Native Pentax K lenses in our database (170 total). Also adaptable: T-mount (T2), M42 screw mount, Deckel (DKL), Tamron Adaptall, M39 / LTM (Leica thread).
- Samyang 8mm f/3.5 Fish-Eye CS 8 mm
- Samyang 10mm f/2.8 ED AS NCS CS 10 mm
- Laowa 12mm f/2.8 Zero-D 12 mm
- Samyang 14mm f/2.8 AE ED AS IF UMC 14 mm
- Laowa 15mm F/4 Wide Angle Macro 15 mm
- Samyang 16mm f/2.0 ED AS UMC CS 16 mm
- Samyang 20mm f/1.8 ED AS UMC 20 mm
- Samyang 24mm f/1.4 ED AS IF UMC 24 mm
- Samyang T-S 24mm f/3.5 ED AS UMC 24 mm
- Laowa 60mm f/2.8 2X Ultra-Macro 60 mm
- Samyang 85mm f/1.4 IF UMC Aspherical 85 mm
- Samyang 135mm f/2 ED UMC 135 mm
- Sigma 4.5mm f/2.8 EX DC HSM circular fisheye 4.5 mm
- Sigma 8-16mm f/4.5-5.6 DC HSM 8–16 mm
- Pentax smc Pentax-DA Fish-Eye 10-17mm f/3.5-4.5 ED IF 10–17 mm
- Sigma 10-20mm f/3.5 EX DC HSM 10–20 mm
- Sigma 10-20mm f/4-5.6 EX DC 10–20 mm
- Sigma 10mm f/2.8 EX DC Fisheye HSM 10 mm
- Tamron SP AF 10-24mm f/3.5-4.5 Di II LD Aspherical (IF) 10–24 mm
- Pentax HD Pentax-DA* 11-18mm f/2.8 ED DC AW 11–18 mm
- Tamron SP AF 11-18mm f/4.5-5.6 Di-II LD Aspherical (IF) 11–18 mm
- Pentax smc Pentax-DA 12-24mm f/4 ED AL IF 12–24 mm
- Sigma 12-24mm F4.5-5.6 II DG HSM 12–24 mm
- Sigma 12-24mm f/4.5-5.6 EX DG Aspherical HSM 12–24 mm
- Pentax smc PENTAX-DA 14mm F2.8 ED[IF] 14 mm
- Sigma 14mm f/2.8 EX 14 mm
- Sigma 14mm f/2.8 EX Aspherical HSM 14 mm
- Sigma 14mm f/3.5 EX 14 mm
- Pentax HD Pentax-D FA 15-30mm f/2.8 ED SDM WR 15–30 mm
- Pentax smc Pentax-DA 15mm f/4 ED AL Limited 15 mm
- Sigma 15-30mm f/3.5-4.5 EX DG Aspherical 15–30 mm
- Sigma 15mm f/2.8 EX DG Diagonal Fisheye 15 mm
- Pentax HD Pentax DA* 16-50mm f/2.8 ED PLM AW 16–50 mm
- Pentax HD Pentax-DA 16-85mm f/3.5-5.6 ED DC WR 16–85 mm
- Pentax smc Pentax-DA 16-45mm f/4 ED AL 16–45 mm
- Pentax smc Pentax-DA* 16-50mm f/2.8 ED AL IF SDM 16–50 mm
Similar cameras#
Other APS-C cameras from around the same time.
- Nikon D40 2006
- Nikon D60 2008
- Nikon D7000 2010
- Sony Alpha 65 2011
- Nikon D7100 2013
- Samsung Galaxy NX 2013
- Sony Alpha 58 2013
- Sony Alpha 77 II 2014
- Ricoh Pentax K-3 II 2015
- Nikon D5600 2016
- Ricoh Pentax KP 2017
- Nikon Z50 2019
Frequently asked questions#
What is the crop factor of the Pentax K-3 III Monochrome?
The Pentax K-3 III Monochrome has a crop factor of 1.55× relative to 35 mm full frame (diagonal 28.0 mm vs 43.3 mm).
What size is the Pentax K-3 III Monochrome sensor?
23.3 × 15.5 mm (APS-C), an area of 361 mm² — 42% of full frame.
Is the Pentax K-3 III Monochrome full frame?
No — its sensor is APS-C, which is 2.4× smaller in area than full frame.
What lens mount does the Pentax K-3 III Monochrome use?
The Pentax K-3 III Monochrome uses the Pentax K (flange distance 45.46 mm).
How long can I expose the night sky with the Pentax K-3 III Monochrome?
With a 13 mm lens (20 mm equivalent) the 500 rule gives 25 s.
Sources & licences#
- Lensfun camera database — CC BY-SA 3.0
Last updated October 03, 2026 · How we calculate · Sources