Ultra-wide prime · Medium format

Fujifilm GF23mmF4 R LM WR

The Fujifilm GF23mmF4 R LM WR is a medium format prime lens (23 mm, f/4) for Fujifilm G-mount. It belongs to the ultra-wide prime class — ideal for astrophotography, landscapes and dramatic perspectives.

23 mmf/4Fujifilm G-mount
23 mm
Focal length
f/4
Maximum aperture
100°
Diagonal angle of view (Medium format)
Medium format
Designed for

Specifications#

Model
GF23mmF4 R LM WR
Lens type
Ultra-wide prime
Focal length
23 mm
Maximum aperture
f/4
Image circle
Medium format (43.8×32.9 mm)
Projection
Rectilinear
Autofocus motor
linear motor (LM)
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 23 mmEquiv. aperture (DoF)
Full frame23 mm · 86°f/4.0
APS-C34 mm · 63°f/6.0
APS-C (Canon)37 mm · 60°f/6.4
Micro Four Thirds46 mm · 50°f/8.0
Medium format 44×3318 mm · 100°f/3.2

Depth of field & background blur#

Computed on its native Medium format format (CoC 38 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.

FocalApertureat 1 mat 2 mat 5 mat 10 mHyperfocalBlur @2 m
23 mmf/460.9 cm3.35 m∞∞3.50 m0.2%
23 mmf/81.64 m∞∞∞1.76 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 23 mmNPF at 23 mm, f/4
Full frame1/25 s22 s14 s
APS-C1/30 s14 s11 s
APS-C (Canon)1/40 s14 s11 s
Micro Four Thirds1/50 s11 s10 s

Frequently asked questions#

Is the Fujifilm GF23mmF4 R LM WR full frame?

No — it is designed for Medium format sensors.

What is the Fujifilm GF23mmF4 R LM WR equivalent to on APS-C?

Its focal length is already the real value for Medium format: 23 mm frames like 18 mm on full frame.

What is the Fujifilm GF23mmF4 R LM WR 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