Wide-angle prime · APS-C

Pentax smc Pentax-DA 15mm f/4 ED AL Limited

The Pentax smc Pentax-DA 15mm f/4 ED AL Limited is a APS-C prime lens (15 mm, f/4) for Pentax K. It belongs to the wide-angle prime class — ideal for street, environmental portraits, landscapes and astro.

15 mmf/4Pentax K
15 mm
Focal length
f/4
Maximum aperture
86°
Diagonal angle of view (APS-C)
APS-C
Designed for

Specifications#

Brand
Pentax
Model
smc Pentax-DA 15mm f/4 ED AL Limited
Lens type
Wide-angle prime
Focal length
15 mm
Maximum aperture
f/4
Image circle
APS-C (23.5×15.6 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 formatAt 15 mmEquiv. aperture (DoF)
APS-C22 mm · 86°f/6.0
APS-C (Canon)24 mm · 84°f/6.4
Micro Four Thirds30 mm · 72°f/8.0

Depth of field & background blur#

Computed on its native APS-C format (CoC 20 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: 16 mm f/4 on aps-c.

FocalApertureat 1 mat 2 mat 5 mat 10 mHyperfocalBlur @2 m
15 mmf/477.6 cm5.27 m∞∞2.89 m0.1%
15 mmf/82.58 m∞∞∞1.45 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 15 mmNPF at 15 mm, f/4
APS-C1/25 s22 s17 s
APS-C (Canon)1/25 s21 s17 s
Micro Four Thirds1/30 s17 s16 s

Adapt it to other systems#

Frequently asked questions#

Is the Pentax smc Pentax-DA 15mm f/4 ED AL Limited full frame?

No — it is designed for APS-C sensors. On a full-frame body it vignettes or triggers crop mode.

What is the Pentax smc Pentax-DA 15mm f/4 ED AL Limited equivalent to on APS-C?

Its focal length is already the real value for APS-C: 15 mm frames like 23 mm on full frame.

What is the Pentax smc Pentax-DA 15mm f/4 ED AL Limited good for?

As a wide-angle prime it suits street, environmental portraits, landscapes and astro.

Sources & licences#

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