Ultra-wide prime · Full frame

Samyang AF 18mm f/2.8

The Samyang AF 18mm f/2.8 is a full frame prime lens (18 mm, f/2.8) for Sony E-mount. It belongs to the ultra-wide prime class — ideal for astrophotography, landscapes and dramatic perspectives.

18 mmf/2.8Sony E-mount
18 mm
Focal length
f/2.8
Maximum aperture
100°
Diagonal angle of view (Full frame)
Full frame
Designed for

Specifications#

Brand
Samyang
Model
AF 18mm f/2.8
Lens type
Ultra-wide prime
Focal length
18 mm
Maximum aperture
f/2.8
Image circle
Full frame (36×24 mm)
Mount(s)
Sony E-mount
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 formatAt 18 mmEquiv. aperture (DoF)
Full frame18 mm · 100°f/2.8
APS-C27 mm · 76°f/4.2
APS-C (Canon)29 mm · 73°f/4.5
Micro Four Thirds36 mm · 62°f/5.6

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: 20 mm f/2.8 on full frame.

FocalApertureat 1 mat 2 mat 5 mat 10 mHyperfocalBlur @2 m
18 mmf/2.854.4 cm2.79 m∞∞3.88 m0.2%
18 mmf/483.8 cm6.37 m∞∞2.72 m0.1%
18 mmf/83.09 m∞∞∞1.37 m0.1%

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).

BodyMin. handheld shutter (longest focal)500 rule at 18 mmNPF at 18 mm, f/2.8
Full frame1/20 s28 s15 s
APS-C1/25 s19 s12 s
APS-C (Canon)1/30 s17 s12 s
Micro Four Thirds1/40 s14 s11 s

Adapt it to other systems#

Frequently asked questions#

Is the Samyang AF 18mm f/2.8 full frame?

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

What is the Samyang AF 18mm f/2.8 equivalent to on APS-C?

On a 1.5× APS-C body it frames like 27 mm, and like 29 mm on Canon APS-C.

What is the Samyang AF 18mm f/2.8 good for?

As a ultra-wide prime it suits astrophotography, landscapes and dramatic perspectives.

Sources & licences#

Last updated October 03, 2026 · How we calculate · Sources