The Pentax smc Pentax-M 28mm f/2.8 is a 28 mm prime lens with a maximum aperture of f/2.8 for the Pentax K mount. Here are its field of view on different sensors, hyperfocal distances, Milky Way exposure limits and the cameras it fits.
Focal length
28 mm
Max aperture
f/2.8
Mount
Pentax K
Designed for
Full frame
Field of view by sensor
| Sensor | Diagonal angle of view | 35 mm equivalent |
|---|---|---|
| Full frame | 75.4° | 28 mm |
| APS-C (1.5×) | 53.6° | 43 mm |
| Canon APS-C (1.6×) | 51.6° | 45 mm |
| Micro Four Thirds | 42.2° | 56 mm |
Hyperfocal distance
| Focal length | f/2.8 | f/5.6 | f/8 | f/11 | f/16 |
|---|---|---|---|---|---|
| 28 mm | 9.4 m | 4.7 m | 3.3 m | 2.4 m | 1.7 m |
Circle of confusion 0.030 mm (sensor size the lens is designed for).
Longest exposure for sharp stars
| Camera | NPF rule (wide open) | 500 rule |
|---|---|---|
| Full frame (24 MP) | 9.8 s @ f/2.8 | 17.9 s |
| Full frame (45 MP) | 8.2 s @ f/2.8 | 17.9 s |
| APS-C (24 MP) | 7.7 s @ f/2.8 | 11.7 s |
Cameras that fit (43)
- KMZ Zenit 122K
- KMZ Zenit 212K
- KMZ Zenit 312K
- KMZ Zenit KM
- Pentax 35mm film: full frame
- Pentax *ist DL2
- Pentax *ist DL
- Pentax *ist DS2
- Pentax *ist DS
- Pentax *ist D
- Pentax K-m
- Pentax K100D
- Pentax K100D Super
- Pentax K110D
- Pentax K10D
- Pentax K20D
- Pentax K-30
- Pentax K-50
- Pentax K-500
- Pentax K-7
- Pentax K-52010
- Pentax K-5 II2012
- Pentax K-5 IIs
- Pentax K-32013
- Pentax K-3 II2015
- Pentax K-3 III2021
- Pentax K-3 III Monochrome
- Pentax K2000
- Pentax K200D
- Pentax K-x
- Pentax K-r
- Pentax K-S2
- Pentax K-S1
- Pentax K-01
- Pentax KF2022
- Pentax KP2017
- Samsung GX10
- Samsung GX20
- Samsung GX-1S
- Samsung GX-1L
- Pentax K-12016
- Pentax K-1 II2018
- Pentax K-702016
Where to buy
B&H PhotoAmazonKEH (used)MPB (used)FAQ
What is the Pentax smc Pentax-M 28mm f/2.8 equivalent to on APS-C?
About 42 mm (1.5×) or 45 mm on Canon APS-C (1.6×).
Which cameras is the Pentax smc Pentax-M 28mm f/2.8 compatible with?
It fits KMZ Zenit 122K, KMZ Zenit 212K, KMZ Zenit 312K, KMZ Zenit KM, Pentax 35mm film: full frame and more (see the full list above).