Sigma 28-45mm F1.8 DG DN Art

The $1,349 Sigma 28-45mm F1.8 DG DN Art is the brightest full-frame zoom lens we've tested for any system and a successor to the well-regarded 24-35mm F2 DG HSM Art lens for SLRs. The updated version has a slightly tighter starting angle and is available for L-mount and Sony E mirrorless cameras, but the idea is the same: It's a zoom lens that delivers photos on par with fixed focal length primes. If you enjoy making images after the sun sets, regularly cover weddings, or chase the bokeh look, you're sure to adore this zoom. It earns our Editors' Choice award for its peerless combination of image quality and convenience. That said, if you don't mind giving up a bit of light for a broader coverage range, don't count out the superb $1,199 Sigma 24-70mm Art II or the $1,099.99 Sony FE 20-70mm F4 G, both of which are also Editors' Choice winners.

Design: A Bit Bulky, But Not Enormous

The 28-45mm F1.8 bucks the trend of recent zoom lenses that aim to be as compact as possible. At 6.0 by 3.5 inches (HD) and 2.1 pounds, it's quite a bit larger than the Sony FE 24-50mm F2.8 G (2.9 by 3.6 inches, 15.5 ounces), for instance. But the Sigma still takes up less room in your bag than a trio of 28mm, 35mm, and 50mm f/1.8 primes.

(Credit: Jim Fisher)

Given its weight, you should use this lens on a full-size body like the Panasonic Lumix S5 II or Sony a7 IV rather than a slimline Lumix S9 or Sony a7C II. The lens uses an internal zoom design like other premium optics, meaning the barrel doesn't extend as you zoom in. This aspect makes the 28-45mm practical as an everyday carry.

(Credit: Jim Fisher)

The lens covers a relatively wide angle at 28mm and narrows to a standard view at 45mm. (Most professional-grade standard zooms start at 24mm and extend to 70mm.) Although 45mm is a little shy of what most define as standard, it's actually closer to the 43mm diagonal measurement of a full-frame sensor than a 50mm lens. The coverage is quite modest in practice, as you can see in the clip below. It's a trade-off you make for the f/1.8 optics, practical weight, and reasonable price.

Competition: No Direct Peers

The 28-45mm F1.8 doesn't have any direct competition on either the L-mount or E-mount systems. Although it's not available for the same cameras, Canon's RF 28-70mm F2 L USM hits many of the same notes and extends to a medium telephoto range. However, it's a lot pricier at $2,999.99, telescopes to zoom, and weighs a full pound more. Nikon's Z system doesn't include any extra-bright zooms.

(Credit: Jim Fisher)

Of course, several f/2.8 and f/4 alternatives exist for Sony and L-mount owners. As mentioned, Sigma sells the 24-70mm F2.8 DG DN Art II for both systems, which covers a broader range for a few dollars less. You can also step down to the $899 Sigma 28-70mm F2.8 DG DN Contemporary if you don't mind losing some weather protection and wide-angle coverage. Panasonic and Leica offer 24-70mm F2.8 zooms in L-mount at higher prices of $1,999.99 and $2,895, though I haven't reviewed either.

(Credit: Jim Fisher)

Sigma's lenses are all available for E mount, though they compete with glass from Sony and Tamron. The Sony FE 20-70mm F4 G costs about the same and covers the useful 20mm angle, for instance, while the $1,099.99 24-50mm F2.8 G has appeal if you like to travel light. Meanwhile, the professional-grade, $2,299.99 FE 24-70mm F2.8 GM II is optically fantastic. Tamron's $899 28-75mm F2.8 G2 is a fast-focusing value option that provides the weather protection missing from the otherwise similar Sigma 28-70mm Contemporary. Of course, none of these competitors matches the Sigma 28-45mm's f/1.8 aperture.

(Credit: Jim Fisher)

Build: Sturdy, All-Weather Construction

The barrel uses a mix of aluminum and Thermally Stable Composite (TSC), a plastic material Sigma says is just as sturdy as metal. An internal zoom bolsters the lens' weather protection. Sigma's Art series entries feature internal seals that reduce the chance of dust and moisture ingress as a rule, but there's even less chance of pulling dust into your camera system with a lens that doesn't have a telescoping inner barrel. You also presumably won't expose your camera's sensor to the elements as much with this lens since it saves you the trouble of switching between several primes in the field.

(Credit: Jim Fisher)

The front element sports an anti-smudge fluorine coating, a material that makes drops of water bead right off and allows you to wipe away stray fingerprints with just a microfiber cloth. If you want to add a protective or creative filter, the 28-45mm supports the 82mm threaded filter size. I paired it with an H&Y Revoring variable ND filter for long-exposure images in daylight, for example. Videographers are also going to need an ND filter to capture natural motion for 24fps and 30fps footage at wide apertures.

(Credit: Jim Fisher)

Scope of delivery includes the lens, front and rear caps, a reversible petal hood, and a soft, zippered carrying case. Those are all standard accessories for a Sigma Art lens.

Handling: Enough Controls to Satisfy Shutterbugs

Sigma takes advantage of the 28-45mm's oversized surface area by including several sets of controls. Aside from rubberized zoom and manual focus rings, you get an aperture control ring, function buttons, an AF/MF toggle switch, and a few control locks.

(Credit: Jim Fisher)

The zoom ring sits mid-barrel and includes rubber ridges to help you find it by touch and manipulate it with gloves in cold weather. It's well-dampened and appropriately tight; there's no chance of knocking it out of place with incidental contact. Indicators mark the 28, 35, 40, and 45mm focal lengths. I don't have any complaints here.

(Credit: Jim Fisher)

The manual focus ring is further ahead and has a similar exterior, though its ridges are a bit closer together to help you differentiate it from the zoom ring. It's also strongly dampened and has a long focus throw, even for Sony cameras on which it has a nonlinear response. In other words, focus racks depend on how quickly you turn the ring on Sony bodies. It took about 180 degrees to go from the closest to the furthest distance when I tried turning it as quickly as possible. If you get the lens for an L-mount camera, you can configure the ring for either a nonlinear or linear response (focus shifts are uniform regardless of how fast you turn the ring).

(Credit: Jim Fisher)

A third control ring toward the base of the lens provides aperture control. It has a metal finish, sports knurled ridges, and offers either third-stop detents or silent, continuous aperture control—a corresponding Click On/Off switch changes between the two modes. The lens supports an f/1.8-16 aperture range, though you can set it to the "A" position on the ring if you prefer to adjust the f-stop via the camera body. Another lock switch keeps the ring set to either "A" or in its manual adjustment range; when you disengage the lock, you can freely swap between the two modes.

(Credit: Jim Fisher)

Two function buttons sit between the aperture and focus rings; they always perform the same function. The logic here is that you can find a button regardless of how you hold your camera. Most cameras set the lens function buttons to AF-Lock by default, but you're free to remap it.

Focus: A Linear Motor and 1:4 Macro Ability

A High-response Linear Actuator (HLA) motor drives autofocus. I tested the lens with a Sony a7R IV and enjoyed focus drive that's as close to instant as it gets. I didn't experience any lag when I shifted focus from close to distant subjects. Just remember that if you use an a9 or a1 series camera, the 28-45mm tops out at 15fps continuous focus drive, a limitation Sony puts on all third-party lenses. That restriction doesn't apply to L-mount cameras, so you can take full advantage of the Lumix S5 II's 30fps continuous focus, for instance.

(Credit: Jim Fisher)

The optics show a slight change in angle when you rack focus from one subject to another at 28mm but almost none at 45mm. This effect, called focus breathing, can detract from cinematic shots that shift the focus from one subject to another but is otherwise inconsequential. You're most likely to notice it in shots at 28mm with the aperture stopped down, as you can see in the video below. Newer Sony cameras include in-camera breathing compensation, but the function works only with first-party lenses. That's not at all a deal breaker for this zoom as it breathes less than many bright primes without any correction.

The lens focuses as close as 11.9 inches throughout its range, so it produces its largest macro reproduction at 45mm. At 1:4 magnification, it falls a bit outside of the traditional macro zoom definition—a zoom typically needs to get to 1:3 to earn that moniker—but it's still very useful for smaller subjects. I took the zoom to a botanical garden and enjoyed capturing small details in flowers. Optical performance at these close distances is exemplary; there's no sign of the softening effect I saw when I tried the Sigma 24-70mm F2.8 DG DN Art II wide-open at close distances. The 28-45mm F1.8 realizes just a tiny sliver of focus for macro imaging at f/1.8, but in-focus details are sharp. I could clearly spot bits of pollen in photos. Overall, it's a better macro performer than a typical fast prime like the Sigma 35mm F1.4 DG DN Art (1:5.4 magnification) but falls short of the Sony FE 20-70mm F4 G's (1:2.6 magnification).

(Credit: Jim Fisher)

The 28-45mm omits optical stabilization, though its bright optics and the fact that the majority of compatible cameras include in-body image stabilization make that more of an academic concern. Aside from lab tests, I used the 28-45mm entirely handheld. I captured good 1/4-second exposures without too much effort when paired with the stabilized a7R IV, and stretched that to 1/2-second and 1-second when I propped the camera up on a fence. For longer exposures, a tripod is a good idea.

(Credit: Jim Fisher)

Sigma 28-45mm F1.8: In the Lab

I paired the 28-45mm F1.8 with the 60MP Sony a7R IV and Imatest software to check its resolution and distortion characteristics in our test lab. I also looked closely at photos I took in the real world to gauge other aspects of optical performance.

From a resolution standpoint, the zoom lives up to its billing as a replacement for prime lenses. At 28mm and f/1.8-8, it delivers outstanding resolution in the center and good results at the corners for an excellent average (4,500-4,800 lines). It's even better at 35mm, notching outstanding results averaged across the frame from f/1.8-8 (5,000-5,200 lines) and excellent marks at the edges and corners. It's just slightly softer wide-open at 45mm (4,700 lines) but scores in the outstanding range from f/2.8-8 (5,000 lines). These test chart results beat those of some prime lenses, as well as the Sigma 24-70mm F2.8 Art II and Sony FE 24-70mm F2.8 GM II zooms.

(Credit: Jim Fisher)

Resolution takes a slight step backward at f/11-16, but you might still want to use those settings to get the sunstar effect in landscape images. At its narrowest apertures, light scatters as it passes through the lens iris, an effect that both softens details and draws small points of light as multipoint starbursts. I'm pretty happy with the sunstars from the 28-45mm, which have crisp lines and few issues with false color ghosting.

(Credit: Jim Fisher)

The 28-45mm does a good job of avoiding flare in most cases, though it's possible to induce the effect if the sun or another bright light source is directly in the frame. The effect is subtle at the widest apertures (I spotted a small red ghost when I pointed the lens directly at my iPhone's LED light), but you can see some interesting false color and flare effects in the f/2.8-8 range. You can typically avoid issues by slightly shifting your camera's position, but I still recommend using the included hood on sunny days.

(Credit: Jim Fisher)

The optics show some distortion throughout the range, including the bulging barrel effect at 28mm and an inward pincushion curve at 35mm and 45mm. The corners are a bit dark at f/1.8-2.8, as well. It's easy to correct all of those issues. If you use your camera in JPG mode (or for video), it's simply a matter of making sure built-in corrections are enabled in the menu. If you opt for Raw image capture, you need to apply a lens profile in photo editing software. Lightroom Classic can do so automatically upon import, and you can toggle it with a checkbox. Sigma provided me with an early look at the Adobe correction profile, which works perfectly. I expect it to show up for everyone else soon.

(Credit: Jim Fisher)

An f/1.8 lens is ideal for crafting images with a shallow depth of field and smoothly defocused backgrounds. The 28-45mm does so with ease and renders soft background blur that's generally free of distracting elements. Defocused highlights are mostly round at 28mm but take on some slightly odd shapes toward the edges and corners at f/1.8-2. I see some of the cat's eye effect at 45mm and f/1.8-2, but results round out from f/2.8-8. There's no evidence of false color in focus transitions, though I see some onion skin texture in highlights, along with slightly hard edges around brightly defocused points of light. Both effects are subtle, and none of the photos I took with the lens exhibit frenetic, distracting backgrounds—the bokeh is smooth and buttery.

The 28-45mm entirely sidesteps false color from lateral and longitudinal chromatic aberration (LoCA). I couldn't spot any signs of color shift in specular highlights or fringing around tree branches and power lines, all of which are typical problem areas. The Sigma 24-70mm F2.8 Art II shows a lot of LoCA if you zoom in, for comparison. The effect is quite difficult to remove with software, so controlling it optically is paramount.

(Credit: Jim Fisher)

Overall, none of the 28-45mm F1.8's optical flaws is concerning. You can use it at whatever aperture you want without worry and easily get rid of any distortion effects with a correction profile.

(Credit: Jim Fisher)

Verdict: As Good as a Set of Primes

The Sigma 28-45mm F1.8 DG DN Art lens is a one-of-a-kind for both L-Mount and Sony E cameras. It puts the exquisite, bright optics of a prime into a zoom design that covers a reasonable focal range. We expect it to be a hit with pros who cover weddings and events, as well as creators who would otherwise turn to a pair or trio of primes to cover wide and standard angles. We wish it had a bit more zoom power, but its top-notch picture quality, construction, and autofocus response earn the lens our Editors' Choice award. Just don't count out the excellent Sigma 24-70mm F2.8 DG DN Art or Sony FE 20-70mm F4 G if you value broader coverage over an extra-bright aperture.