Standard zoom · APS-C

Pentax smc Pentax-DA L 18-50mm f/4-5.6 DC WR RE

The Pentax smc Pentax-DA L 18-50mm f/4-5.6 DC WR RE is a APS-C zoom lens (18–50 mm, f/4–5.6) for Pentax K. It belongs to the standard zoom class — ideal for everyday shooting, travel, events and walkaround use.

18–50 mmf/4–5.6Pentax K
18–50 mm
Focal length
f/4–5.6
Maximum aperture
76°–32°
Diagonal angle of view (APS-C)
APS-C
Designed for
2.8×
Zoom ratio

Specifications#

Brand
Pentax
Model
smc Pentax-DA L 18-50mm f/4-5.6 DC WR RE
Lens type
Standard zoom
Focal length
18–50 mm
Maximum aperture
f/4–5.6
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 18 mmAt 30 mmAt 50 mmEquiv. aperture (DoF)
APS-C27 mm · 76°45 mm · 50°75 mm · 32°f/6.0
APS-C (Canon)29 mm · 73°48 mm · 48°80 mm · 30°f/6.4
Micro Four Thirds36 mm · 62°60 mm · 40°100 mm · 24°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: 20 mm f/4 on aps-c.

FocalApertureat 1 mat 2 mat 5 mat 10 mHyperfocalBlur @2 m
18 mmf/450.2 cm2.48 m∞∞4.16 m0.2%
18 mmf/81.22 m45.6 m∞∞2.09 m0.1%
30 mmf/417.0 cm70.6 cm5.31 m69.6 m11.5 m0.5%
30 mmf/834.7 cm1.55 m34.1 m∞5.78 m0.2%
50 mmf/46.0 cm24.5 cm1.59 m6.90 m32.0 m1.4%
50 mmf/811.9 cm49.6 cm3.43 m20.3 m16.0 m0.7%

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/4
APS-C1/80 s19 s14 s
APS-C (Canon)1/80 s17 s14 s
Micro Four Thirds1/100 s14 s13 s

Adapt it to other systems#

Frequently asked questions#

Is the Pentax smc Pentax-DA L 18-50mm f/4-5.6 DC WR RE 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 L 18-50mm f/4-5.6 DC WR RE equivalent to on APS-C?

Its focal length is already the real value for APS-C: 18–50 mm frames like 28–77 mm on full frame.

What is the Pentax smc Pentax-DA L 18-50mm f/4-5.6 DC WR RE good for?

As a standard zoom it suits everyday shooting, travel, events and walkaround use.

Sources & licences#

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

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