A 23mm lens? At first glance, 23 might seem to be a strange choice for a focal length (there are no other 23mm lenses in the site's database at review time). However, in this case, 23mm is a perfect choice.
You see, this lens covers only the APS-C image circle, and a 23mm on an APS-C format camera provides the same angle of view as a 34.5mm lens on a full-frame camera (23 x 1.5). 34.5 rounds to the 35mm full-frame angle of view that everyone loves.
The big advantage of covering a smaller image circle is decreased lens element size, which leads to a smaller overall size, lighter weight, and reduced cost, which is reflected in a lower price. The APS-C format Sigma 23mm F1.4 DC DN Contemporary Lens embodies those attributes while still providing an ultra-wide aperture and impressive image quality. This is an attractively designed lens with a high utility focal length.
The focal length (or the focal length range for a zoom lens) is the first consideration for lens selection. Focal length matters because it drives subject distance choices, which determine perspective.
Why choose an APS-C 23mm lens? That this moderately wide angle of view invites a subject distance that creates a natural perspective and makes the viewer feel present in the image is one reason. This focal length is wide enough to capture the big scene but not so wide that people and other subjects are readily distorted by the close perspective invited by ultra-wide angles. It is often easy to sneaker zoom to the right distance to get the ideal 23mm subject framing.
The 23mm focal length is great for general-purpose use, making it an ideal choice to leave on the camera for whatever needs arise. I often press whatever lens I'm reviewing into the around-the-house, walk-around, general-purpose lens role, and 23mm works superbly for this need.
For similar reasons, the 23mm focal length has long been a first choice for photojournalists. Wedding photographers, who work in some of the darkest venues to be found, also frequently use wide aperture 23mm lenses. Portrait photographers like the 23mm focal length for full to mid-body portraits and for group portraits.
The 23mm angle of view is inviting for street photography. Landscape photographers have plenty of uses for the 23mm focal length. This is a great lens to take for a walk with your friends.
Sports photographers able to get close to their subjects (such as basketball shot from over or under the net) or wanting to capture a wider/environmental view of their events appreciate this focal length. The perspective invited by 23mm can make action figures large in the frame.
Parents love 23mm lenses for capturing their indoor events, and most pets will let you get close enough to capture a nice perspective with such a lens. 23mm is popular with videographers, especially for documentary work and vlogging. Many medium and large products are ideally captured at 23mm.
With the ultra-wide f/1.4 aperture available, the night sky is an inviting subject for this lens, and those photographing the night sky frequently target the milky way. The 23mm angle of view is sometimes narrower than optimal for that subject, but the heart of the milky way significantly filling the frame is beautiful. Relative to wider focal lengths, 16mm for example, 23mm requires a faster shutter speed to avoid star trails and provides a shallower depth of field, increasing the challenge of including in-focus foreground subjects in a starry sky image.
Special thanks to the quarry graveyard for the sample pictures.
To visualize where 23mm fits among other common focal lengths, I'll borrow a focal length range example from a zoom lens review.
The full-frame lens's focal lengths were translated to APS-C numbers, explaining the strange focal length choices.
The full list of 23mm uses is huge and limited only by our imaginations.
Few lenses have a max aperture wider than f/1.4, and this wide aperture is a huge advantage.
F/1.4 allows a significant amount of light to reach the imaging sensor. Use that light to enable action (subject and camera) stopping shutter speeds in very low light levels with reasonably low ISO settings keeping noise levels down. It seems there is always enough light for handholding a 23mm lens at f/1.4.
Another advantage of a wide aperture lens is the background blur it can create. While wide-angle lenses are not able to create the strongest blur, this lens set to f/1.4 with a close subject creates a very shallow DOF, drawing the viewer's eye to the in-focus subject against a smoothly blurred background. Add artistic capabilities to this lens's list of highly desired features.
This example illustrates the maximum blur this lens can create:
If you are shooting under a full sun at f/1.4, you will likely need at least 1/8000 sec shutter speeds at ISO 100 to keep the exposure adequately dark. Positive is that there is little action that a 1/8000 sec. shutter speed cannot stop, but if the subject has very bright or reflective colors, even a 1/8000 sec. shutter speed might not be fast enough to avoid blown highlights. Some cameras have an extended ISO setting as low as 50 that can optionally be used in this situation (though the dynamic range may be impacted). Better still is that some cameras have shutter speeds faster than 1/8000 available.
Using a neutral density filter is a good solution for retaining the use of f/1.4 under direct sunlight when the shutter limitation is exceeded, and this is an especially good option for cameras with 1/4000 sec. maximum speeds. Stopping down (narrowing) the aperture is always an option for preventing an image from getting too bright, though stopping down negates the need for the wide f/1.4 aperture, and the subject-isolating shallow depth of field is lost.
Wide apertures require large, heavy, and costly lens elements that directly translate into larger, heavier, and more expensive lenses. As mentioned, covering only the APS-C image circle significantly offsets those disadvantages, and this lens is compact, lightweight, and affordable.
The Sigma 23mm F1.4 DC DN Contemporary Lens is not optically stabilized. Fortunately, Sony takes care of that omission with Steady Shot or IBIS (In-Body Image Stabilization) in their mirrorless cameras. In addition to reducing camera shake, the stabilized imaging sensor provides a still viewfinder image, enabling careful composition. Sensor-based AF takes advantage of the stabilized view for improved accuracy.
With no IS switch on the lens, the camera menu must be accessed to enable or disable IBIS, a slight impediment to working quickly, going from tripod to handholding, for example.
This lens has f/1.4 available, but will the image quality produced at this aperture be good enough to make you want to use it? Fortunately, lens designs have advanced significantly in recent years, my skepticism is on the decline, and this lens produces impressive f/1.4 imagery.
The Sigma 23mm F1.4 DC DN Contemporary Lens is sharp across the entire image circle wide-open at f/1.4.
In general, lenses become sharper as they are stopped down one or two stops from their wide-open apertures. Even stopped down only 1/3 stop to f/1.6, a slight contrast improvement is seen, and at f/2, a slight additional increase in contrast and resolution makes this lens's results extremely sharp.
Often, subjects are not placed in the center of a composition. In the periphery of the image circle, where light rays are refracted to a stronger angle than in the center, lenses typically show decreased sharpness. As mentioned, this lens remains sharp into the corners at f/1.4, and periphery sharpness improvement is seen through f/2.8. F/2.8 corners are impressively sharp.
Taking the testing outdoors, we next look at a series of center-of-the-frame 100% resolution crop examples. These images were captured in RAW format using a Sony Alpha 1 and processed in Capture One using the Natural Clarity method. The sharpening amount was set to only "30" on a 0-1000 scale. Note that images from most cameras require some level of sharpening, but too-high sharpness settings are destructive to image details and hide the deficiencies of a lens.
These results, including those captured at f/1.4, are sharp.
Next, we'll look at a series of comparisons showing 100% resolution extreme corner crops captured and processed identically to the above center-of-the-frame images. The lens was manually focused in the corner of the frame to capture these images. The first two sets are from the top left of the frame, and the third set was from the bottom right.
Samples taken from the outer extreme of the image circle, full-frame corners, usually show a lens's weakest performance. These results are remarkably sharp.
Does corner sharpness matter? Sometimes it does, and sometimes it doesn't, and high-performing lenses such as this one are there for you when it does.
This lens does not exhibit focus shift, the plane of sharp focus moving forward or backward as the aperture is narrowed (residual spherical aberration or RSA).
A lens is expected to show peripheral shading at the widest aperture settings when used on a camera that utilizes its entire image circle. At f/1.4, expect about 2.5 stops of corner shading. Stopping down one stop to f/2 reduces the shading by about 1 stop to 1.5 stops. The vignetting reduction comes to an end at f/2.8, with about 0.7 stops of peripheral shading remaining through f/16.
One-stop of shading is often used as the visibility number, though subject details provide a widely varying amount of vignetting discernibility. Vignetting is correctable during post-processing, with increased noise in the brightened areas the penalty, or it can be embraced, using the effect to draw the viewer's eye to the center of the frame. Study the pattern shown in our vignetting test tool to determine how your images will be affected.
If you find a camera that allows full-frame mode with an APS-C lens attached, such as the Sony Alpha 7R IV in this case, the mechanical vignetting will appear as in the above image.
Lateral (or transverse) CA (Chromatic Aberration) refers to the unequal magnification of all colors in the spectrum. Lateral CA shows as color fringing along lines of strong contrast running tangential (meridional, right angles to radii), with the mid and especially the periphery of the image circle showing the most significant amount as this is where the most significant difference in the magnification of wavelengths typically exists.
With the right lens profile and software, lateral CA is often easily correctable (often in the camera) by radially shifting the colors to coincide. However, it is always better to avoid this aberration in the first place.
Color misalignment can be seen in the site's image quality tool, but let's also look at a worst-case example. The image below is a 100% crop from the extreme top left corner of a Sony a1 frame showing diagonal black and white lines.
Only black and white colors should be present in these images, with the additional colors indicating a noticeable but not strong presence of lateral CA.
A relatively common lens aberration is axial (longitudinal, bokeh) CA, which causes non-coinciding focal planes of the various wavelengths of light. More simply, different colors of light are focused to different depths. Spherical aberration, along with spherochromatism, or a change in the amount of spherical aberration with respect to color (looks quite similar to axial chromatic aberration but is hazier) are other common lens aberrations to observe. Axial CA remains somewhat persistent when stopping down, with the color misalignment effect increasing with defocusing. The spherical aberration color halo shows little size change as the lens is defocused, and stopping down one to two stops generally removes this aberration.
In the real world, lens defects do not exist in isolation, with spherical aberration and spherochromatism generally found, at least to some degree, along with axial CA. These combine to create a less sharp, hazy-appearing image quality at the widest apertures.
The examples below look at the defocused specular highlights' fringing colors in the foreground vs. the background. The lens has introduced any fringing color differences from the neutrally colored subjects.
The color separation at the wide end is noticeable, but not unusually so. The f/4 and f/5.6 results are nice. Note that color blur complicates precise focus determination.
Bright light reflecting off lens elements' surfaces may cause flare and ghosting, resulting in reduced contrast and sometimes interesting, usually destructive visual artifacts. The shape, intensity, and position of the flare and ghosting effects in an image are variable, dependent on the position and nature of the light source (or sources), selected aperture, shape of the aperture blades, and quantity and quality of the lens elements and their coatings. Additionally, flare and ghosting can impact AF performance.
This lens's Super Multi-Layer Coating does an outstanding job of limiting flare and ghosting. This lens produced practically no flare effects even at narrow apertures in our standard sun in the corner of the frame flare test.
Flare effects can be embraced or avoided, or removal can be attempted. Unfortunately, removal is sometimes very challenging, and in some cases, flare effects can destroy image quality. Thus, high flare resistance is a welcomed trait of this lens.
Two lens aberrations are particularly evident in images of stars, mainly because bright points of light against a dark background make them easier to see. Coma occurs when light rays from a point of light spread out from that point instead of being refocused as a point on the sensor. Coma is absent in the center of the frame, gets worse toward the edges/corners, and generally appears as a comet-like or triangular tail of light that can be oriented either away from the center of the frame (external coma) or toward the center of the frame (internal coma). The coma clears as the aperture is narrowed. Astigmatism is seen as points of light spreading into a line, either sagittal (radiating from the center of the image) or meridional (tangential, perpendicular to sagittal). This aberration can produce stars appearing to have wings. Remember that Lateral CA is another aberration apparent in the corners.
The image below is a 100% crop taken from the top-left corner of a Sony Alpha 1 image captured at f/1.4.
While this performance is not unusual, these stars have wings.
This lens has moderate barrel distortion. This geometric distortion will not be revealed in many scenarios, but a straight line running along the edge of the frame will have a noticeable bend, inviting correction.
Reasons for allowing geometric distortion in a lens design include lower cost, smaller size, and lighter weight. Most modern lenses have correction profiles available (including in-camera), and the distortion can be corrected using these. Still, distortion correction is destructive at the pixel level as some portion of the image must be stretched or the overall dimensions reduced.
As seen earlier in the review, it is easy to illustrate the strongest blur a lens can create. Due to the infinite number of variables present among available scenes, assessing the bokeh quality is considerably more challenging. Here are some 100% crop f/11 (for diaphragm blade interaction) examples.
These examples appear normal.
Except for a small number of specialty lenses, the wide aperture bokeh in the frame's corner does not produce round defocused highlights, with these effects taking on a cat's eye shape due to a form of mechanical vignetting. If you look through a tube at an angle, similar to the light reaching the frame's corner, the shape is not round. That is the shape we're looking at here.
As the aperture narrows, the entrance pupil size is reduced, and the mechanical vignetting diminishes, with the f/2.8 corner shapes already looking great.
A 9-blade count diaphragm will create 18-point sunstars (diffraction spikes) from point light sources captured with a narrow aperture. Generally, the more a lens diaphragm is stopped down, the larger and better shaped the sunstars tend to be. Wide aperture lenses tend to have an advantage in this regard, and this lens can produce outstanding stars, as illustrated in the f/16 example below.
This lens's design features 3 SLD and 2 aspherical elements.
The Sigma 23mm F1.4 DC DN Contemporary Lens is optically a solid performer. You may sometimes want to correct the barrel distortion, some color separation is present at wide apertures, and f/1.4 vignetting is noticeable, but this lens's sharpness will be the strong overriding factor for most.
Driven by a stepping motor, the Sigma 23mm F1.4 DC DN Contemporary Lens autofocuses smoothly with good speed. Focusing is internal with a slight buzz audible. Focus accuracy, of utmost importance, is reliable.
With adequate contrast on the subject, this lens focuses in extremely dark environments. As usual, autofocusing becomes very slow in the lowest functioning light levels.
Normal is for the scene to change size in the frame (sometimes significantly) as the focus is pulled from one extent to the other. This is focus breathing, a change in focal length resulting from a change in focus distance. Focus breathing impacts photographers intending to use focus stacking techniques, videographers pulling focus, and anyone critically framing while adjusting focus. This lens produces a big change in subject size through a full-extent focus distance adjustment.
This lens does not have an AF/MF switch. Changing this frequently used camera setting requires the use of the menu system (or a camera switch on some models).
The 23mm F1.4 DC DN Contemporary Lens's large, sharp-ribbed, rubberized focus ring is easy to find and rotates smoothly with ideal resistance.
This lens has a variable adjustment rate based on the rotation speed. A full-extent focus distance change requires one full rotation (360°) when turning the focus ring slowly. Turn the ring fast, and 200° of rotation does the same.
With a minimum focus distance of 9.8" (250mm), this lens has a relatively low 0.14x maximum magnification spec.
With no identical alternative lenses in the database, the chart below includes a set of complementary Sigma lenses.
|Sigma 16mm F1.4 DC DN Contemporary Lens||9.8"||(250mm)||0.10x|
|Sigma 23mm F1.4 DC DN Contemporary Lens||9.8"||(250mm)||0.14x|
|Sigma 24mm F1.4 DG DN Art Lens||9.8"||(250mm)||0.14x|
|Sigma 30mm F1.4 DC DN Contemporary Lens||11.8"||(300mm)||0.14x|
|Sigma 56mm F1.4 DC DN Contemporary Lens||19.7"||(500mm)||0.14x|
|Sigma 18-50mm F2.8 DC DN Contemporary Lens||4.8"||(121mm)||0.36x|
A subject measuring approximately 5.1 x 3.4" (129.5 x 86.3mm) fills the imaging sensor at this lens's minimum MF distance.
The USPS love stamps shared above have an image area that measures 1.05 x 0.77" (26.67 x 19.558mm), and the overall individual stamp size is 1.19 x 0.91" (30.226 x 23.114mm).
Wide-open, this lens produces sharp center of the frame details at minimum focus distance, expect the deep corners to be soft due to field curvature. The corners look very nice at f/2.8, but strong lateral CA remains throughout the aperture range.
Mount an extension tube behind this lens to significantly decrease and increase the minimum focus distance and higher magnification. As of review time, Sigma does not publish extension tube specs or manufacture these items, but third-party Sony-compatible extension tubes are available.
This lens is not compatible with Sigma teleconverters.
The Sigma 23mm F1.4 DC DN Contemporary Lens has an attractive design that maintains tight tolerances and has a quality finish. The gently tapering barrel diameter leads to this lens's only moving feature, the long, straight, and comfortable-to-use focus ring.
The Sigma 23mm F1.4 DC DN Contemporary Lens features a TSC (Thermally Stable Composite) exterior. "TSC is a state-of-the-art polycarbonate that is designed to be both lightweight and extremely durable, and its chemical makeup means it doesn’t shrink or expand with changing temperatures. This material is so high-quality that we’re also incorporating it into our Art and Sports lenses to provide lightness and thermal consistency." [Sigma]
180° of the barrel's mount area features molded-in ribs that facilitate grip for mounting and dismounting the lens.
This lens has no buttons or switches. As hinted earlier, I miss the AF/MF button the most. Positive is that the lack of switches means increased reliability and decreased opportunity for dirt and moisture penetration.
"Are Contemporary lenses weather sealed? Contemporary lenses feature a gasket at the mount that protects against dust and moisture, but none feature sealing throughout the lens body (this is an additional reason that Contemporary lenses are more affordable). That said, the vast majority of contaminants work their way into lenses through the rear mount, so as long as they aren’t abused, these lenses will provide many years of trouble-free use, even in moderate weather. For regular use in more extreme conditions, Art or Sports lenses are the way to go." [Sigma]
Fluorine coating to repel water drops and dust and facilitate cleaning is not applied to the front element.
This Sigma lens is compatible with advanced mirrorless camera features, including Eye AF, in-camera lens correction (shading, chromatic aberration, distortion), and camera-based lens firmware updates.
Aided by the reduced APS-C sensor image circle size requirement, the 23mm F1.4 DC DN lens is very small and light for its focal length and aperture specifications. Compare this lens against the full frame 24mm F1.4 DG DN to gain an understanding of the difference.
|Model||Weight oz(g)||Dimensions w/o Hood "(mm)||Filter||Year|
|Sigma 16mm F1.4 DC DN Contemporary Lens||14.3||(405)||2.8 x 3.6||(72.2 x 92.3)||67||2021|
|Sigma 23mm F1.4 DC DN Contemporary Lens||12.0||(340)||2.6 x 3.0||(65.8 x 76.9)||52||2023|
|Sigma 24mm F1.4 DG DN Art Lens||18.0||(510)||3.0 x 3.8||(75.7 x 97.5)||72||2022|
|Sigma 30mm F1.4 DC DN Contemporary Lens||9.4||(265)||2.6 x 2.9||(64.8 x 73.3)||52||2016|
|Sigma 56mm F1.4 DC DN Contemporary Lens||9.9||(280)||2.6 x 2.3||(66.5 x 59.5)||55||2018|
|Sigma 18-50mm F2.8 DC DN Contemporary Lens||10.2||(290)||2.5 x 2.9||(64.5 x 74.5)||55||2017|
For many more comparisons, review the complete Sigma 23mm F1.4 DC DN Contemporary Lens Specifications using the site's lens specifications tool.
Here is a visual comparison:
Positioned above from left to right are the following lenses:
The same lenses are shown below with their hoods in place.
Use the site's product image comparison tool to visually compare the Sigma 23mm F1.4 DC DN Contemporary Lens to hundreds of other lenses.
This lens uses small and relatively inexpensive 52mm filters. A standard-thickness circular polarizer filter does not increase peripheral shading. Still, a slim model such as the Breakthrough Photography X4 may be appreciated if shared with a wider-angle lens.
Sigma includes hoods with their lenses, and the LH554-01 Lens Hood ships with the 23mm F1.4 DC DN Contemporary Lens. The LH554-01 offers good protection to the front lens element, including protection from dust, water, fingers, limbs, etc., and from flare-inducing bright light.
The hood's interior is mold-ribbed for reduced internal reflections, and the rigid plastic build absorbs some impact, adding a layer of physical protection to the camera and lens. The rear portion of the hood is rubberized to, along with the mold-ribbed ring next to it, facilitate installation and removal, and the petal shape makes installation alignment easy.
A lens case is not included in the box.
The low price of this lens high-performing lens should launch it to the best-seller list. The 23mm F1.4 DC DN Contemporary Lens is another great Sigma value.
The "DC" in the name indicates that this lens provides an image circle wide enough to cover (only) an APS-C imaging sensor, and the "DN" indicates that this lens was designed for short flange mirrorless cameras. The Sigma 56mm F1.4 DC DN Contemporary Lens is available in Sony E, Leica L, and Fujifilm X mounts.
Made in Japan, each Art lens is tested with Sigma's proprietary MTF measuring system, ensuring a quality product. Regarding the Sony E-mount version of this lens, Sigma develops, manufactures, and sells lenses based on the specifications of the E-mount, disclosed by Sony Corporation under license agreement.
Sigma provides a 1-year limited warranty, and Sigma USA provides a limited 3-year warranty extension.
The reviewed Sigma 23mm F1.4 DC DN Contemporary Lens was on loan from Sigma USA.
Without direct alternative lenses to compare, I'll make some broader comparisons. Adding 7mm to the focal length, let's start with the next longer sibling, the Sigma 30mm F1.4 DC DN Contemporary Lens.
In the image quality comparison, the 23mm lens is slightly sharper. The 30mm lens has slightly less peripheral shading and shows slightly more flare effects.
The Sigma 23mm F1.4 DC DN vs. 30mm F1.4 DC DN Contemporary comparison shows the 30mm lens modestly smaller and lighter. Many will view the 30's substantially less expensive price as the biggest differentiator between these two lenses, aside from the focal length difference.
Let's go 7mm wider and compare the Sigma 16mm F1.4 DC DN Contemporary Lens. In the image quality comparison, the 23mm lens is obviously sharper. The 16mm lens has modestly less peripheral shading at the widest apertures but shows modestly stronger flare effects in the site's test.
The Sigma 23mm F1.4 DC DN vs. 16mm F1.4 DC DN Contemporary Lens comparison shows the 23mm lens is considerably smaller and modestly lighter. The larger lens uses 67mm filters vs. 52mm. The 23mm lens has a 0.14x maximum magnification vs. 0.10x. The 16mm lens is considerably less expensive.
Again, the focal length difference is a big one. Choose the right angle of view for the need.
The Sigma 24mm F1.4 DG DN Art Lens differs by only 1mm, but the full-frame image circle coverage is a big deal.
The image quality comparison I have available requires strong visualization skills to discern, but the 23mm lens does not appear lacking in the APS-C coverage area. The full-frame lens has a big advantage of less peripheral shading in the APS-C area, and it has less barrel distortion.
The Sigma 23mm F1.4 DC DN Contemporary vs. 24mm F1.4 DG DN Art Lens comparison shows the 24mm lens considerably larger and 50% heavier and priced about 50% higher. The 24mm lens has 11 aperture blades vs. 9 and uses 72mm filters vs. 52mm. Most will select the lens to match the camera sensor format.
Use the site's tools to create additional comparisons.
And then there were 4. The 23mm F1.4 DC DN Contemporary Lens joins Sigma's "F1.4 Mirrorless Trio", the 16mm F1.4 DC DN, 30mm F1.4 DC DN, and 56mm F1.4 DC DN Contemporary Lenses. The quartet of lenses ia highly complementary to each other, sharing many similarities.
The compact, lightweight Sigma 23mm F1.4 DC DN Contemporary Lens is a superb choice for general-purpose, around-the-house, and other applications advantaged by the 23mm APS-C angle of view and wide f/1.4 aperture. This is a fun-to-use lens, and viewing at the results is even more fun.
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