Leica Summicron-TL 1:2/23 Asph. Specs & DoF

23 mm

Focal length

f/2

Maximum aperture

63°

Diagonal angle of view (APS-C)

APS-C

Designed for

Specifications#

Brand: Leica
Model: Summicron-TL 1:2/23 Asph.
Lens type: Wide-angle prime
Focal length: 23 mm
Maximum aperture: f/2
Image circle: APS-C (23.5×15.6 mm)
Mount(s): L-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 format	At 23 mm	Equiv. aperture (DoF)
APS-C	34 mm · 63°	f/3.0
APS-C (Canon)	37 mm · 60°	f/3.2
Micro Four Thirds	46 mm · 50°	f/4.0

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: 24 mm f/2 on aps-c.

Focal	Aperture	at 1 m	at 2 m	at 5 m	at 10 m	Hyperfocal	Blur @2 m
23 mm	f/2	14.5 cm	59.8 cm	4.26 m	32.4 m	13.5 m	0.6%
23 mm	f/4	29.5 cm	1.28 m	16.1 m	∞	6.79 m	0.3%
23 mm	f/8	63.1 cm	3.55 m	∞	∞	3.40 m	0.1%

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).

Body	Min. handheld shutter (longest focal)	500 rule at 23 mm	NPF at 23 mm, f/2
APS-C	1/30 s	14 s	8 s
APS-C (Canon)	1/40 s	14 s	8 s
Micro Four Thirds	1/50 s	11 s	7 s

Compatible cameras#

Bodies in our database with a native L-Mount mount. Full-frame bodies switch to an APS-C crop with this lens.

Adapt it to other systems#

Sony E-mount Nikon Z Fujifilm X-mount Canon EF-M Hasselblad XCD Nikon 1 (CX)Pentax Q

Similar lenses#

Viltrox AF 23mm F1.4 XF/Z/L f/1.4
Panasonic S 24mm f/1.8 f/1.8
Sigma 24mm F2 DG DN | Contemporary 021 f/2
Sigma 24mm F3.5 DG DN | Contemporary 021 f/3.5
Sigma 24mm f/1.4 DG HSM | A f/1.4
Sigma 28mm F1.4 DG HSM | Art f/1.4
Leica Elmarit-TL 1:2.8/18 Asph. f/2.8
Sigma 16mm f/1.4 DC DN Contemporary f/1.4

Frequently asked questions#

Is the Leica Summicron-TL 1:2/23 Asph. full frame?

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

What is the Leica Summicron-TL 1:2/23 Asph. equivalent to on APS-C?

Its focal length is already the real value for APS-C: 23 mm frames like 35 mm on full frame.

What is the Leica Summicron-TL 1:2/23 Asph. good for?

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

Sources & licences#

Lensfun lens database — CC BY-SA 3.0