Pentax smc Pentax-M 50mm f/2 Specs, Equivalents & Depth of Field

50 mm

Focal length

f/2

Maximum aperture

47°

Diagonal angle of view (Full frame)

Full frame

Designed for

Specifications#

Brand: Pentax
Model: smc Pentax-M 50mm f/2
Lens type: Standard prime
Focal length: 50 mm
Maximum aperture: f/2
Image circle: Full frame (36×24 mm)
Mount(s): Pentax K
Projection: Rectilinear
Lensfun correction profile: Yes — distortion/vignetting/TCA

Equivalent focal length on different cameras#

Field of view and depth-of-field equivalence when this lens is used on bodies with different sensor sizes (natively or via an adapter).

Camera format	At 50 mm	Equiv. aperture (DoF)
Full frame	50 mm · 47°	f/2.0
APS-C	75 mm · 32°	f/3.0
APS-C (Canon)	80 mm · 30°	f/3.2
Micro Four Thirds	100 mm · 24°	f/4.0

Depth of field & background blur#

Computed on its native Full frame format (CoC 30 µm). “Blur @2 m” is the size of an out-of-focus point at infinity, as a percentage of frame width, with the subject at 2 m — a simple bokeh index. Full table: 50 mm f/2 on full frame.

Focal	Aperture	at 1 m	at 2 m	at 5 m	at 10 m	Hyperfocal	Blur @2 m
50 mm	f/2	4.6 cm	18.8 cm	1.21 m	5.06 m	41.7 m	1.8%
50 mm	f/4	9.1 cm	37.8 cm	2.52 m	12.4 m	20.9 m	0.9%
50 mm	f/8	18.4 cm	77.6 cm	6.14 m	218 m	10.5 m	0.4%

Handheld & night-sky limits#

NPF assumes typical 20–24 MP sensors (≈6 µm pixels on full frame, ≈3.9 µm on APS-C, ≈3.3 µm on Micro Four Thirds).

Body	Min. handheld shutter (longest focal)	500 rule at 50 mm	NPF at 50 mm, f/2
Full frame	1/50 s	10 s	5 s
APS-C	1/80 s	7 s	4 s
APS-C (Canon)	1/80 s	6 s	4 s
Micro Four Thirds	1/100 s	5 s	3 s

Compatible cameras#

Bodies in our database with a native Pentax K mount.

Adapt it to other systems#

Sony E-mount Canon RF Nikon Z Fujifilm X-mount Micro Four Thirds L-Mount Canon EF-M Fujifilm G-mount Hasselblad XCD Nikon 1 (CX)Pentax Q Samsung NX Canon EF Nikon F

Similar lenses#

Pentax smc Pentax-A 50mm f/1.4 f/1.4
Pentax smc Pentax-A 50mm f/1.7 f/1.7
Pentax smc Pentax-FA 50mm f/1.4 f/1.4
Pentax smc Pentax-FA 50mm f/1.7 f/1.7
Pentax smc Pentax-M 50mm f/1.4 f/1.4
Pentax smc Pentax-M 50mm f/1.7 f/1.7
Sigma 50mm f/1.4 EX DG HSM f/1.4
Voigtländer Nokton 58mm F1.4 SLII f/1.4
Pentax smc Pentax-FA 43mm f/1.9 Limited f/1.9
Pentax smc Pentax-DA 40mm f/2.8 Limited f/2.8
Pentax smc Pentax-DA 40mm f/2.8 XS f/2.8
Pentax smc Pentax-DA 35mm f/2.4 AL f/2.4

Frequently asked questions#

Is the Pentax smc Pentax-M 50mm f/2 full frame?

Yes — it covers the full 36 × 24 mm frame.

What is the Pentax smc Pentax-M 50mm f/2 equivalent to on APS-C?

On a 1.5× APS-C body it frames like 75 mm, and like 80 mm on Canon APS-C.

What is the Pentax smc Pentax-M 50mm f/2 good for?

As a standard prime it suits street, documentary, everyday and low-light shooting.

Sources & licences#

Lensfun lens database — CC BY-SA 3.0