Samyang 21mm F 1 4 ED AS UMC CS Review | 54 Data compared

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  • Avg. price: ~£300
  • Lens mount: Canon EF-M, Fujifilm X, Sony E, Micro Four Thirds
  • Maximum focal length: 21 mm
  • Maximum aperture (telephoto end): 1.4
  • Optical image stabilization: no
  • Maximum angle of view: 69.3 °

Samyang 21mm F 1 4 ED AS UMC CS review. Compare 54 technical specifications and user reviews to see how it ranks among camera lenses and if it is worth buying.

7.0

Overall score

What it is: An overall evaluation of the camera lens's quality, based on technical analyses and user reviews.

When it matters: When you need a quick reference to identify the best camera lenses on the market.

Score components:

80.0%

7.0

Technical Score

20.0%

7.1

User score

Very good
7.0

Technical Score

What it is: An assessment of the camera lens's technical performance, covering eight key areas: sharpness, aperture flexibility, autofocus, stabilization, build quality, mount compatibility, close-focus performance, and design.

When it matters: When you want to compare camera lenses based on technical performance and available features.

Score components:

35.0%

8.4

Optics & Aperture

24.0%

7.2

Build & Handling

20.0%

5.4

Focus & Controls

10.0%

9.0

Lab Scores

8.0%

4.2

Stabilization

3.0%

1.0

Mount & Format

Very good
7.1

User score

What it is: A rating that combines user reviews and the total number of reviews received by the camera lens.

When it matters: When real-world owner satisfaction and review volume matter to your decision.

Score components:

70.0%

8.3

User reviews

30.0%

4.4

Popularity

User score:
United Kingdom
amazon
4.0
(29)
amazon
4.1
(22)
United States
Amazon_logo.png
4.2
(50)

(Reviews last updated: July 2026)

Very good
  • 7.3
    Low-light photography

    Score components:

    70.0%

    10

    Maximum aperture (telephoto end)

    30.0%

    1.0

    Optical image stabilization

  • 5.0
    Travel

    Score components:

    30.0%

    ?

    Lens length

    25.0%

    8.6

    Lens diameter

    25.0%

    1.0

    Weather sealing (splashproof)

    20.0%

    1.0

    Optical image stabilization

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Best prices in UK

Best rankings

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Available: ranking among products currently available (including other versions of this product).
All: ranking among all products in the database.

Verdict

The Samyang 21mm f/1.4 ED AS UMC CS is a fast, manual-focus wide-angle prime lens designed for mirrorless cameras with APS-C and Micro Four Thirds sensors, providing a full-frame equivalent focal length of approximately 31.5mm to 42mm. Its optical construction features 8 elements in 7 groups, including one extra-low dispersion (ED) element and three aspherical (ASP) elements, along with Ultra Multi-Coating (UMC) to minimize flare and ghosting. Key pros include its bright f/1.4 maximum aperture for low-light performance, a lightweight and compact build (approx. 275-290g), smooth internal focusing with a 0.28m minimum distance, and high central sharpness. Main cons are the complete lack of autofocus and electronic contacts, which results in no EXIF data being transmitted to the camera, as well as noticeable chromatic aberration and corner softness when shooting wide open.

Technical Specifications of Samyang 21mm F 1 4 ED AS UMC CS

Technical Score

What it is: An assessment of the camera lens's technical performance, covering eight key areas: sharpness, aperture flexibility, autofocus, stabilization, build quality, mount compatibility, close-focus performance, and design.

When it matters: When you want to compare camera lenses based on technical performance and available features.

Score components:

35.0%

8.4

Optics & Aperture

24.0%

7.2

Build & Handling

20.0%

5.4

Focus & Controls

10.0%

9.0

Lab Scores

8.0%

4.2

Stabilization

3.0%

1.0

Mount & Format

7.0
Samyang 21mm F 1 4 ED AS UMC CS has a technical score of 7 points, which is lower than 57.6% of camera lenses.
User score

What it is: A rating that combines user reviews and the total number of reviews received by the camera lens.

When it matters: When real-world owner satisfaction and review volume matter to your decision.

Score components:

70.0%

8.3

User reviews

30.0%

4.4

Popularity

User score:
United Kingdom
amazon
4.0
(29)
amazon
4.1
(22)
United States
Amazon_logo.png
4.2
(50)

(Reviews last updated: July 2026)

7.1
Samyang 21mm F 1 4 ED AS UMC CS has a user score of 7.15 points, which is lower than 84% of camera lenses.
Popularity
What it is: An indicator based on the number of reviews received by the camera lens.
When it matters: When you want to see which camera lenses attract the most buyer attention and review activity.
4.4
Samyang 21mm F 1 4 ED AS UMC CS has a popularity of 4.4 points, which is lower than 62.2% of products in this category.
Ratio quality/price

What it is: An indicator that combines the camera lens's overall rating with its cost.

When it matters: When you want to know how much overall quality you get for the price.

Score components:

60.0%

7.0

Overall score

40.0%

8.9

Price

7.6
Samyang 21mm F 1 4 ED AS UMC CS has a quality-to-price ratio of 7.6 points, which is higher than 64.9% of products in this category.
Lens type
What it is: The optical category that indicates whether the lens is a prime, zoom, macro, fisheye, or another design.
When it matters: When you are choosing between a prime, zoom, macro, or specialty lens for the kind of subjects you shoot.

Importance: LOW

prime
Lens mount
What it is: The mechanical and electronic interface that determines which cameras the lens can be attached to.
When it matters: When camera compatibility and access to the right lens ecosystem are central to your buying decision.

Importance: LOW

Canon EF-M, Fujifilm X, Sony E, Micro Four Thirds
Sensor format coverage
What it is: The largest sensor size the lens is designed to cover without severe vignetting.
When it matters: When you need the lens to fully cover your camera sensor without heavy corner darkening.

Importance: LOW

APS-C
Filter thread size
What it is: The diameter of the front filter thread used for screw-in filters and compatible accessories.
When it matters: When you plan to use screw-in filters such as polarizers, ND filters, or protective glass.

Importance: LOW

58 mm
Teleconverter compatibility
What it is: Whether the lens can be used with compatible teleconverters to extend focal length.
When it matters: When you want to extend reach for wildlife or sports without changing to a different long lens.

Importance: HIGH

no
Samyang 21mm F 1 4 ED AS UMC CS does not support teleconverters. 15.3% of camera lenses support teleconverters.
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Minimum focal length
What it is: The shortest focal length the lens can provide, which determines its widest framing.
When it matters: When wide framing matters for landscapes, interiors, architecture, or travel shots.

Importance: LOW

21 mm
Maximum focal length
What it is: The longest focal length the lens can reach, which determines its telephoto reach.
When it matters: When you need more reach for wildlife, sports, stage events, or distant details.

Importance: LOW

21 mm
Optical zoom
What it is: The ratio between the longest and shortest focal lengths available in the lens zoom range.
When it matters: When you want one lens to cover a broader range of compositions without swapping glass.

Importance: LOW

?
Maximum angle of view
What it is: The widest scene the lens can capture at its shortest focal length.
When it matters: When you need to fit more of a room, skyline, or landscape into the frame.

Importance: LOW

69.3 °
Minimum angle of view
What it is: The narrowest scene the lens captures at its longest focal length.
When it matters: When you want tighter framing on faraway subjects without moving closer.

Importance: LOW

69.3 °
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Focus motor
What it is: The autofocus drive system responsible for moving lens elements into focus.
When it matters: When fast, quiet autofocus matters for video, wildlife, street shots, or moving subjects.

Importance: LOW

N/A
Minimum focus distance
What it is: The shortest distance at which the lens can focus on a subject.
When it matters: When you like shooting details, food, flowers, or products from a very short distance.

Importance: MEDIUM

0.28 m
Samyang 21mm F 1 4 ED AS UMC CS focuses as close as 0.28 m, which is closer than 57.1% of camera lenses and equal to 6.6% of camera lenses.
Maximum reproduction ratio
What it is: The highest magnification the lens can achieve when focusing at its closest distance.
When it matters: When close-up magnification matters for macro work, textures, or small product details.

Importance: MEDIUM

0.2x
Samyang 21mm F 1 4 ED AS UMC CS reaches a reproduction ratio of 0.2x, which is higher than 50.8% of camera lenses and equal to 7% of camera lenses.
Full-time manual focus
What it is: The ability to adjust focus manually without leaving autofocus mode.
When it matters: When you want to fine-tune focus instantly without switching out of autofocus.

Importance: HIGH

no
Samyang 21mm F 1 4 ED AS UMC CS does not support full-time manual focus. 68.4% of camera lenses support full-time manual focus.
Manual-focus-only lens.
Internal focusing
What it is: A focusing design in which internal elements move while the outer barrel length stays unchanged.
When it matters: When you use polarizers, gimbals, or close-up setups that benefit from a lens that does not extend while focusing.

Importance: HIGH

yes
Samyang 21mm F 1 4 ED AS UMC CS supports internal focusing. 83.6% of camera lenses support internal focusing.
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Optical image stabilization
What it is: A hardware system that shifts optical elements to counteract camera shake and reduce blur.
When it matters: When you want steadier handheld shots and less blur, especially in low light or at longer focal lengths.

Importance: HIGH

no
Samyang 21mm F 1 4 ED AS UMC CS does not support optical image stabilization. 29% of camera lenses include optical image stabilization.
Stabilization effectiveness (CIPA stops)
What it is: The rated stabilizer benefit, measured in stops, under CIPA testing standards.
When it matters: When you are comparing stabilized lenses and want to know how much handheld shutter-speed advantage they offer.

Importance: HIGH

?
Weight
What it is: The total mass of the lens, affecting portability and handling balance on the camera body.
When it matters: When you carry a lens all day for travel, hiking, or event coverage and want to keep your kit manageable.

Importance: HIGH

?
Lens length
What it is: The physical length of the lens body from mount to front edge.
When it matters: When bag space, balance, or front clearance matters in a compact travel or video setup.

Importance: HIGH

?
Lens diameter
What it is: The widest outer diameter of the lens barrel.
When it matters: When grip comfort, filter size, or fit inside a tight camera bag matters to you.

Importance: MEDIUM

64.3 mm
Samyang 21mm F 1 4 ED AS UMC CS has a diameter of 64.3 mm, which is slimmer than 84.4% of camera lenses and equal to that of 0.1% of camera lenses.
Weather sealing (splashproof)
What it is: Protective sealing intended to resist splashes, dust, and light environmental exposure.
When it matters: When you often shoot outdoors in light rain, dust, or changing conditions.

Importance: HIGH

no
Samyang 21mm F 1 4 ED AS UMC CS does not support weather sealing. 50.3% of camera lenses support weather sealing.
Metal mount
What it is: A lens mount made of metal rather than plastic for greater durability at the camera connection point.
When it matters: When durability matters because you change lenses often or use heavier gear for work.

Importance: HIGH

yes
Samyang 21mm F 1 4 ED AS UMC CS uses a metal lens mount. 93.1% of camera lenses use a metal lens mount.
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DxOMark overall score
What it is: The combined DxOMark lens rating based on lab-tested optical performance.
When it matters: When you want a quick lab-based summary of overall optical performance before comparing lenses in detail.

Importance: HIGH

?
DxOMark sharpness score
What it is: The DxOMark subscore that reflects how much detail the lens can resolve across the frame.
When it matters: When fine detail matters for landscapes, product work, or high-resolution cameras.

Importance: HIGH

?
DxOMark transmission
What it is: The measured light transmission of the lens, expressed as T-stop rather than nominal f-number.
When it matters: When real light loss matters for exposure consistency in studio, cinema, or mixed-lens shoots.

Importance: MEDIUM

?
DxOMark distortion
What it is: The DxOMark metric that measures how much the lens bends straight lines away from their true shape.
When it matters: When straight lines matter in architecture, interiors, copy work, or product photography.

Importance: MEDIUM

?
DxOMark vignetting
What it is: The DxOMark measurement of corner darkening relative to the center of the image.
When it matters: When even corner brightness matters for skies, studio backdrops, or clean product shots.

Importance: MEDIUM

?
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Samyang 21mm F 1 4 ED AS UMC CS vs the average camera lens

  • 1.4 lower f-number at telephoto end
    Samyang 21mm F 1 4 ED AS UMC CS has a brighter maximum telephoto aperture than the average camera lens (f/1.4 vs f/2.8). The average lens has a maximum telephoto aperture of f/2.8.
    What it is: The widest aperture available at the long end of the zoom range, affecting light intake and background blur.
    When it matters: When you shoot at the long end in low light or want stronger background blur for portraits and sports.

    Importance: HIGH

    Samyang 21mm F 1 4 ED AS UMC CS has a brighter maximum telephoto aperture than the average camera lens (f/1.4 vs f/2.8). The average lens has a maximum telephoto aperture of f/2.8.1.4 vs 2.8
  • Has aperture ring
    Samyang 21mm F 1 4 ED AS UMC CS has an aperture ring, the average camera lens does not. 31.2% of camera lenses include an aperture ring.
    What it is: A dedicated ring on the lens used to control the aperture directly.
    When it matters: When you want direct tactile control over exposure while shooting photos or video.

    Importance: MEDIUM

    Samyang 21mm F 1 4 ED AS UMC CS has an aperture ring, the average camera lens does not. 31.2% of camera lenses include an aperture ring.
  • Has focus distance scale
    Samyang 21mm F 1 4 ED AS UMC CS has a focus distance scale, the average camera lens does not. 48.6% of camera lenses include a focus distance scale.
    What it is: A marked scale that shows the approximate focus distance set on the lens.
    When it matters: When you pre-focus manually for street, zone focusing, or repeatable tripod setups.

    Importance: MEDIUM

    Samyang 21mm F 1 4 ED AS UMC CS has a focus distance scale, the average camera lens does not. 48.6% of camera lenses include a focus distance scale.
  • 12.7 mm narrower lens barrel
    Samyang 21mm F 1 4 ED AS UMC CS is slimmer than the average camera lens (64.3 mm vs 77 mm). The average lens has a diameter of 77 mm.
    What it is: The widest outer diameter of the lens barrel.
    When it matters: When grip comfort, filter size, or fit inside a tight camera bag matters to you.

    Importance: MEDIUM

    Samyang 21mm F 1 4 ED AS UMC CS is slimmer than the average camera lens (64.3 mm vs 77 mm). The average lens has a diameter of 77 mm.64.3 mm vs 77 mm
  • 1 more aspherical elements
    Samyang 21mm F 1 4 ED AS UMC CS has more aspherical elements than the average camera lens (3 vs 2). The average lens has 2 aspherical elements.
    What it is: Specially shaped lens elements used to reduce distortion and improve sharpness with fewer optical compromises.
    When it matters: When edge sharpness and lower distortion matter in wide-angle, travel, or everyday shooting.

    Importance: MEDIUM

    Samyang 21mm F 1 4 ED AS UMC CS has more aspherical elements than the average camera lens (3 vs 2). The average lens has 2 aspherical elements.3 vs 2
  • 1.4 lower f-number at telephoto end
    Samyang 21mm F 1 4 ED AS UMC CS has a brighter maximum telephoto aperture than the average camera lens (f/1.4 vs f/2.8). The average lens has a maximum telephoto aperture of f/2.8.
  • 1 more aspherical elements
    Samyang 21mm F 1 4 ED AS UMC CS has more aspherical elements than the average camera lens (3 vs 2). The average lens has 2 aspherical elements.
  • Has aperture ring
    Samyang 21mm F 1 4 ED AS UMC CS has an aperture ring, the average camera lens does not. 31.2% of camera lenses include an aperture ring.
  • Has focus distance scale
    Samyang 21mm F 1 4 ED AS UMC CS has a focus distance scale, the average camera lens does not. 48.6% of camera lenses include a focus distance scale.
  • 12.7 mm narrower lens barrel
    Samyang 21mm F 1 4 ED AS UMC CS is slimmer than the average camera lens (64.3 mm vs 77 mm). The average lens has a diameter of 77 mm.
  • 1 fewer low-dispersion elements
    Samyang 21mm F 1 4 ED AS UMC CS has fewer low-dispersion elements than the average camera lens (1 vs 2). The average lens has 2 low-dispersion elements.
  • No full-time manual focus
    Samyang 21mm F 1 4 ED AS UMC CS does not support full-time manual focus, the average camera lens does. 68.4% of camera lenses support full-time manual focus.
    Manual-focus-only lens.
  • Not weather-sealed
    Samyang 21mm F 1 4 ED AS UMC CS does not support weather sealing, the average camera lens does. 50.3% of camera lenses support weather sealing.
  • Older release date
    Samyang 21mm F 1 4 ED AS UMC CS was released earlier than the average camera lens.
    September 2015
  • Not weather-sealed
    Samyang 21mm F 1 4 ED AS UMC CS does not support weather sealing, the average camera lens does. 50.3% of camera lenses support weather sealing.
    What it is: Protective sealing intended to resist splashes, dust, and light environmental exposure.
    When it matters: When you often shoot outdoors in light rain, dust, or changing conditions.

    Importance: HIGH

    Samyang 21mm F 1 4 ED AS UMC CS does not support weather sealing, the average camera lens does. 50.3% of camera lenses support weather sealing.
  • No full-time manual focus
    Samyang 21mm F 1 4 ED AS UMC CS does not support full-time manual focus, the average camera lens does. 68.4% of camera lenses support full-time manual focus.
    Manual-focus-only lens.
    What it is: The ability to adjust focus manually without leaving autofocus mode.
    When it matters: When you want to fine-tune focus instantly without switching out of autofocus.

    Importance: HIGH

    Samyang 21mm F 1 4 ED AS UMC CS does not support full-time manual focus, the average camera lens does. 68.4% of camera lenses support full-time manual focus.
  • 1 fewer low-dispersion elements
    Samyang 21mm F 1 4 ED AS UMC CS has fewer low-dispersion elements than the average camera lens (1 vs 2). The average lens has 2 low-dispersion elements.
    What it is: Optical elements designed to reduce color fringing by controlling how different wavelengths focus.
    When it matters: When you want cleaner edges and less color fringing in high-contrast scenes.

    Importance: MEDIUM

    Samyang 21mm F 1 4 ED AS UMC CS has fewer low-dispersion elements than the average camera lens (1 vs 2). The average lens has 2 low-dispersion elements.1 vs 2
  • 13.2% lower user score
    Samyang 21mm F 1 4 ED AS UMC CS has a lower user score than the average camera lens (7.15 vs 8.091).
    What it is: A rating that combines user reviews and the total number of reviews received by the camera lens.
    When it matters: When real-world owner satisfaction and review volume matter to your decision.
    Samyang 21mm F 1 4 ED AS UMC CS has a lower user score than the average camera lens (7.15 vs 8.091).7.15 vs 8.09
  • Older release date
    Samyang 21mm F 1 4 ED AS UMC CS was released earlier than the average camera lens.
    September 2015
    What it is: The date when the lens model was first officially introduced.
    When it matters: When you prefer a newer optical design with more modern autofocus, coatings, or stabilization features.

    Importance: LOW

    Samyang 21mm F 1 4 ED AS UMC CS was released earlier than the average camera lens.2015 vs 2016

Graphic comparison of Samyang 21mm F 1 4 ED AS UMC CS and

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Third-party reviews

United States

(Reviews last updated: July 2026)

What customers like about Samyang 21mm F 1 4 ED AS UMC CS?

  • Excellent center sharpness even at wide apertures
  • Fast f/1.4 maximum aperture ideal for low light
  • Compact and lightweight design well-suited for mirrorless bodies
  • Strong overall build quality with a metal mount
  • Effective control of lateral chromatic aberrations and distortion
  • Smooth and nicely damped manual focus ring
  • High contrast and pleasing bokeh characteristics

What customers dislike about Samyang 21mm F 1 4 ED AS UMC CS?

  • Manual focus only with no electronic contacts for EXIF data
  • Noticeable softness at the corners and edges when wide open
  • Significant vignetting (corner shading) at large apertures
  • Lack of a hyperfocal distance scale on the lens barrel
  • No optical image stabilization (OIS)
  • Aperture ring adjustments are limited to 1/2 EV stops rather than 1/3
  • Vulnerable to flare in specific bright lighting conditions

Expert reviews

E
ephotozine.com
06/10/2015
Summary of the review
T
trustedreviews.com
24/02/2016
Summary of the review
W
whatdigitalcamera.com
24/02/2016
Summary of the review
A
amateurphotographer.com
18/03/2023
Summary of the review
L
lenstip.com
08/12/2015
Summary of the review
D
dustinabbott.net
01/03/2016
Summary of the review
M
mirrorlessons.com
27/07/2016
Summary of the review
F
fuji-x-forum.de
17/04/2016
Summary of the review
D
derjackistweg.de
06/03/2016
Summary of the review
L
lesnumeriques.com
07/04/2016
Summary of the review
O
ollo.it
N/A
Summary of the review

Video reviews

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