Sigma 18-35mm f/1.8 DC HSM Art Lens Review

The word "groundbreaking" seems inadequate for describing the awesomeness of the Sigma 18-35mm f/1.8 DC HSM Art Lens. The primary reason for that awesomeness is the not-seen-in-any-other-zoom-lens f/1.8 aperture. In fact, f/1.8 is 1 1/3 stops wider/faster than the next-widest/fastest f/2.8 zoom lens crowd – allowing more than twice as much light to reach the camera sensor than the tied-for-second place lenses. The f/1.8 max aperture, available over the entire focal length range, puts this zoom lens on a shelf by itself. Per Sigma, it is a world's first.

Just because a lens has a specific max aperture does not mean that you will want to use that aperture, but this lens rocks at f/1.8. Combine excellent wide open image quality with a great looking, great performing and modest fixed-sized package along with a good price and you have a lens that is going to find a home in MANY kits. The downsides? A relatively short focal length range and lack of image stabilization are the only ones on my list.

Let's start the review with a look at the focal length range as that is one of my primary criteria for lens selection. You need the focal length that is going to allow proper framing and proper perspective for your subjects. The "DC" ("Digital Camera") in the name means that this lens is compatible only with ASP-C/1.6x FOVCF sensor format DSLR cameras. My APS-C format general purpose lens minimum focal length range recommendation is 18-45mm, which relates to 28.8-72mm in full frame format.

The Sigma 18-35mm f/1.8 DC HSM Art lens's focal length range covers only a subset of my recommended range – equating to a 28.8-56mm angle of view on a full frame camera. That this lens does not meet my minimal focal length range desires for a general purpose lens is going to be overlooked by most – this range need being offset by the low light and background blurring capabilities made possible by the f/1.8 max aperture.

Being long on the wide end and short on the long end, 18-35mm still works well for many landscape photography uses. While landscape photography does not so-frequently need the f/1.8 aperture advantage this lens holds, the right weather conditions (very overcast to eliminate hotspots with some rain to drive away other visitors – and add saturation), a sweet loaner car (my car was in the shop) and this lens needing a workout provided far more motivation than I needed to schedule a day trip to Ricketts Glen State Park. From this location comes this review's focal length range examples.

Load Comparison Images

The Sigma 18-35mm f/1.8 DC HSM Art Lens is one of the first members of Sigma's Global Vision Lens lineup. Global Vision lenses receive designations of "A" for Art, "C" for Contemporary or "S" for Sports. While I'm loving what Sigma is doing with their lenses right now, I'm not yet a fan of limiting the usefulness of a lens to one of these categories (and what does "Contemporary" mean for a lens designation? Will it still be contemporary in 10 years? Are the "A" and "S" lenses not just as contemporary?).

The 18-35 f/1.8 wears an "A" badge. And I'm sure that the wide "A"perture is largely responsible for this classification. Wide apertures mean shallow depth of field. Shallow depth of field can mean that the subject pops from a blurred background. Blurring the background is of course easiest at longer focal lengths – and 35mm is not a long focal length.

The image below shows a 35mm f/1.8 example focused at approximately 6' (1.8m). Click on the image to see a complete 18mm and 35mm aperture comparison. You may be surprised at how in-focus-appearing the background appears at 18mm f/1.8 in a 650px high size-reduced image.

The bottom line is that the f/1.8 aperture enables a more-strongly blurred background than that f/2.8 zoom alternative you were considering (identical focal lengths compared).

While I suppose that any image can be classified as art, my definition for art imagery is far narrower – and this lens has far broader usefulness than my definition's limitations. The landscape photography use I mentioned above is only the tip of the iceberg for this lens's complete usefulness list.

It seems that I am finding a new use for this lens every day. I've had the 18-35 mounted to my 60D and available for immediate use since it arrived over two weeks ago. It has been a great choice for capturing the daily memories of life. Some examples of which you will find throughout this review.

The 18-35mm focal length is rather wide angle for most sports needs, but this lens certainly can be used for the narrow niche of athletic activities these focal length work for. The f/1.8 aperture is extremely desirable for sports captures – especially the indoor varieties. Near-court basketball photography for example.

Capturing an indoor or other low light people event? This lens is a good choice.

With few exceptions, every lens can be used as a portrait lens. But not every lens is good for all types of portraits. The perspective required for tight 18-35mm portraits make this lens a bad choice for such – unless you want to get "artistic". Notice the big nose and small hands in the sample picture below? This lens will be better-used for half-body and more-loosley cropped portraits – and for group portraits.

Load Comparison Images

The above image was captured at 18mm, f/1.8 using a Canon EOS 60D at a not-kind-for-faces close focus distance. The 100% crop provides a glimpse of the sharp image quality this lens delivers at f/1.8. That performance is from a low DPP sharpness setting of "2" – the lowest setting I regularly use with the 60D.

Another factor making the relatively short focal length range more palatable is the image quality this lens delivers. Especially at f/1.8 where this lens delivers good sharpness across the entire frame. Sharpness is slightly better at the wide end than the long end, but f/1.8 real life images from both ends look good. Stopping down to f/2.8 will improve sharpness modestly, but you are going to have difficulty seeing the f/2.8 to f/4 difference in your images. The 35mm corners appreciate a narrower aperture the most.

Frequently, wide aperture lenses used on the largest sensor format camera they support, show significant amounts of vignetting – which negates some of the wide aperture advantage. This lens breaks that stereotype. It is not vignetting free, but the 1.4 to 1.6 stops of corner vignetting at f/1.8 is relatively mild for an f/1.8 lens. By f/4, the peripheral shading is essentially gone.

A wide angle lens with a wide aperture, sharp across-the-frame wide open aperture image quality and low vignetting begs to be used for night sky photography. And this lens is a good choice for such use.

Stars in the corner of a frame tend to bring out another lens aberration – coma. Coma turns your little round stars into Martian space ships. I'm happy to report that the 18-35 shows only slight effects from coma in only the extreme frame corners.

The Sigma 18-35 shows some CA (Chromatic Aberration) in the corners at the wide end of the focal length range. Very little CA remains at 24mm.

I mentioned that rain chases visitors away from state parks. A significant storm not showing on the radar arrived suddenly not long after arriving at Ricketts Glen SP. Though the 18-35 is not waterproof, I was prepared for rain. But, with the car being still close by and the rain too hard to shoot through, I went for cover. But lens testing never stops.

This control dial in the car is monochrome. The extra colors are not supposed to be there. What you are seeing is often referred to as bokeh CA – CA that shows in the out of focus portions of the image. This anomaly will only be noticeable in similar shooting situations.

Wide angle focal lengths make it more difficult to get a blurred background, but wide apertures make it easier. The Sigma 18-35mm f/1.8 DC HSM Art Lens has both. As can be seen in the dial control image above, this lens can create a strong blur at 35mm if the subject is close and the aperture is wide. Use a more-distant background to create more background blur.

Zoom out and stop the lens down (narrower aperture – higher aperture number) and creating a background blur becomes more difficult. But it can still be done. Here is an 18mm f/5.6 example.

From this example, we can see that the 9-blade aperture delivers rather smooth out of focus highlights with a touch of bright edge. The blur quality in my real life applications has been nice.

With the sun in the corner of the frame, the Sigma 18-35 shows little flare from a wide open f/1.8 aperture. Flare slowly increases as the aperture narrows until becoming noticeable at f/8 and by f/16, strong flaring is obvious.

Most 16, 17 or 18mm-to-something-mm lenses show noticeable barrel distortion at their widest focal length. This lens has barrel distortion at 18mm, but it performs better than many similar lenses by showing only a modest amount. As usual, the barrel distortion is corrected as the focal length increases until essentially being gone at around 22mm. Pincushion distortion then creeps into the picture and becomes mild from 28 through 35mm.

Overall, I am pleased with the image quality from this first-ever lens design. It has a green light for my own needs.

Featuring Sigma's HSM (Hypersonic Motor) driven AF, the Sigma 18-35mm f/1.8 DC HSM Art Lens focuses with good speed. It is not the fastest-focusing lens made, but it is far from the slowest. Focusing is quiet with only some clicks being heard as final focus adjustments are nailed down.

This is an internally-focusing lens with FTM (Full Time Manual) focusing available. Filters installed on this lens will not rotate during focusing.

Great for video recording is that subjects do not change size with focusing. They go into and out of focus of course, but they do not grow or shrink while doing so. The image remains solidly-centered during focus changes.

At short distances, this lens is practically parfocal (focus distance settings remains the same throughout the zoom range). Longer distance focusing likes more focus adjustment through the available focal length range. Sigma provides as many focus distance markings as can reasonably be fit into the space available for them in the window.

This lens is compatible with the Sigma Dock. The USB dock allows the lens's firmware to be updated (bug fixes, compatibility updates, etc.) and allows precise focus calibration. On the test charts and using the Datacolor SpyderLensCal, the 18-35 f/1.8 focused accurately with excellent consistently. Check out the 5 focus accuracy test samples below.

Load Comparison Images

You don't see any difference between those images? No difference is what you want to see. And the "0" is where the sharpest focus should be. The were 15 other identical images, but I couldn't see the point of boring you with the rest of the samples.

In the field, AF has been performing well, but not perfectly. I did find occassional AF misses. Especially when working near this lens's MFD (Minimum Focus Distance).

I know – sorry about the creepy subject. Sometimes these situations just fall into my lap. My wife, using her unmistakable slightly panicked voice, called me to our finished basement to eradicate this little monster. Upon arrival on the scene, I decided that the 3.25" (82.5mm) Wolf Spider would make a great subject.

As I said before, the Sigma 18-35 has been a great lens to have available for around-the-house use and has been glued to my 60D since it arrived. I grabbed it, a Canon 600EX-RT Speedlight, a Speedlite Transmitter ST-E3 RT and a small softbox and returned to the scene of the home invasion. As I gathered the gear, the stress level was being increased as my wife learned that I had left the hairy creature alive and unattended.

Fortunately, the spider remained findable. Since the carpet was not the background I wanted, I slid a piece of printer paper under it. That was of course much easier to say than to do.

The above picture was captured at the 18-35's minimum focus distance. The rest of the photo details: 35mm, ISO 100, f/8.0, 1/160. I released the spider outside as the carpet would have needed cleaning if I had squished it as requested.

At MFD, one shot AF was backfocusing a high percentage of the time. But, with the Sigma Dock and SOP app, this issue is correctable. Autofocus can be in-lens calibrated for four focus distances at 18mm, 24mm, 28mm and 35mm.

Wider focal lengths make fast-action subjects suitable for safe for tight framing difficult to find, but I did find the 18-35 f/1.8's AI Servo AF to perform reasonably well in such circumstances.

This lens's 0.23x MM (Maximum Magnification) specification is decent – quite good compared to the f/2.8 zoom lenses containing similar focal lengths. The spider image above examples 0.23x. Of course, from a high resolution camera, a subject captured at 0.23x magnification can be printed or displayed at many times life size. The chart below shows the referenced comparison with the f/2.8 zoom lenses.

Model	Min Focus Distance "(mm)		Max Magnification
Canon EF 16-35mm f/2.8 L II USM Lens	11.0	(280)	0.22x
Canon EF-S 17-55mm f/2.8 IS USM Lens	13.8	(350)	0.16x
Sigma 17-50mm f/2.8 EX DC OS HSM Lens	11.0	(280)	0.20x
Sigma 18-35mm f/1.8 DC HSM A Lens	11.0	(280)	0.23x
Tamron 17-50mm f/2.8 XR Di II Lens	10.6	(270)	0.22x
Tamron 17-50mm f/2.8 XR Di II VC Lens	11.4	(290)	0.21x
Tokina 16-28mm f/2.8 AT-X Pro FX Lens	11.0	(280)	0.19x

Need more magnification? Extension tubes are your best option as this lens is not compatible with Sigma's extenders.

The images below show all of the available APS-C and larger format DSLR zoom lenses with an aperture wider than f/2.8.

Load Comparison Images

That's right – there is only one.

All of the review-time-current Sigma Global Vision lenses have a really nice physical appearance with a feel that at least equals the look. The high quality look matches nicely with the high quality build of these lenses.

The Sigma 18-35mm f/1.8 DC HSM Art Lens has smooth, perfectly-damped and ideally-sized zoom and focus rings that have no play in them. Note that the zoom ring rotates in the Nikon standard direction (opposite of Canon's standard zoom ring rotation direction). Only the ribbed rubber surface portion of the zoom ring extends beyond the lens barrel diameter and the forward-positioned (where I want it) focus ring is raised only slightly more than the lens barrel, for an overall smooth design that feels great in hand.

This lens is slightly narrow and slightly long relative to other lenses in its class. If you can call any other lens in the same class. For lack of better options, I list the 16, or 17mm-to-something f/2.8 zoom lenses for comparison.

Model	Weight oz(g)		Dimensions w/o Hood "(mm)		Filter	Year
Canon EF 16-35mm f/2.8 L II USM Lens	22.6	(640)	3.5 x 4.4	(88.5 x 111.6)	82mm	2007
Canon EF-S 17-55mm f/2.8 IS USM Lens	22.8	(645)	3.3 x 4.4	(83.5 x 110.6)	77mm	2006
Sigma 17-50mm f/2.8 EX DC OS HSM Lens	19.9	(565)	3.3 x 3.6	(83.5 x 91.8)	77mm	2010
Sigma 18-35mm f/1.8 DC HSM A Lens	28.6	(811)	3.1 x 4.8	(78 x 121)	72mm	2013
Tamron 17-50mm f/2.8 XR Di II Lens	15.3	(434)	3.2 x 2.9	(81.7 x 74)	67mm	2006
Tamron 17-50mm f/2.8 XR Di II VC Lens	20.1	(570)	3.1 x 3.7	(79.6 x 94.5)	72mm	2009
Tokina 16-28mm f/2.8 AT-X Pro FX Lens	33.5	(950)	3.5 x 5.2	(90 x 133.3)	n/amm	2011

For many more comparisons, review the complete Sigma 18-35mm f/1.8 DC HSM Art Lens Specifications using the site's Lens Spec tool.

The somewhat dense weight in a modestly-sized, quality-built package gives the 18-35mm f/1.8 lens a solid feel. As recently introduced with the Sigma 120-300mm f/2.8 DG OS Sports Lens, Sigma utilizes Thermally Stable Composite (TSC) materials in the build of this lens. TSC combines the characteristics of metal and polycarbonate and has the thermal expansion/contraction properties of aluminum. "Since thermal shrinkage is low, [TSC] has a high affinity to metal parts ..." and permits size reduction in other mechanical parts including the zoom ring. TSC also has a considerably higher elasticity compared to Sigma's other products.

Note that this is not a weather-sealed lens.

The 72mm filter size is a common one. These filters are not too large or too pricey. I can see only a slight amount of vignetting being caused by a standard thickness CP filter at 18mm f/1.8.

Positioned above from left to right in their fully retracted positions are the following lenses:

Sigma 17-50mm f/2.8 EX DC OS HSM Lens
Canon EF-S 17-55mm f/2.8 IS USM Lens
Canon EF 16-35mm f/2.8 L II USM Lens
Sigma 18-35mm f/1.8 DC HSM Art Lens

The same lenses are shown below in their fully extended states with their lens hoods in place.

The Sigma 18-35 has an attractive, clean, slender, smooth design that, if I haven't made it clear already, I like a lot.

As with all Sigma lenses, the lens hood is included in the box. The rear of this modestly-sized hood has a rubberized surface that makes it easy to grasp for bayonet installation/removal. Sigma's recently improved lens cap design is also easy to grasp for installation or removal.

Sigma includes a nice padded, zippered nylon case in the box. The case has a 1.75" (440mm) belt loop for attaching to a slim belt (or narrow thick belt).

Want to know what year your lens was made? With a Sigma Global Vision lens, determining the answer to this question is easy – just prefix a "2" to the three-digit number engraved near the lens mount.

The Sigma 18-35mm f/1.8 DC HSM Art Lens is available in Canon (reviewed), Nikon, Pentax, Sony/Minolta and Sigma mounts. Changing camera brands? Sigma has announced their "Mount Conversion Service" to protect your investment.

My standard disclaimer: There are potential issues with third party lenses. Since Sigma reverse engineers (vs. licenses) manufacturer AF algorithms, there is always the possibility that a DSLR body might not support a (likely older) third party lens. Sometimes a lens can be made compatible by the manufacturer, sometimes not. There is also the risk of a problem that results in the lens and body manufacturers directing blame at each other. Compatibility with the Sigma Dock is risk reducing. Sigma USA's 3-year warranty is superior to Canon's standard 1 year warranty (Sigma's international warranty is also 1 year).

I see this lens as having two limitations. The first is the lack of optical stabilization. Sigma stated the "It already was a tough challenge for us to develop a high-spec lens with F1.8 throughout its zoom range. This time, our first priority [was] to achieve the 1.8 constant aperture. Incorporation of OS function [will] be our next step."

The f/1.8 aperture reduces the need for OS in scenarios where the reduced depth of field work is acceptable (or preferred). The f/2.8 zoom lenses with optical stabilization are handholdable in even lower light levels when the subject is not moving.

The other limitation I see in the 18-35 f/1.8 is the limited focal length range relative to the other APS-C-only 17 or 18mm to something zoom lenses. When asked if the limited focal length range design was necessary to keep the lens size manageable and the cost affordable, Sigma responded: "Increasing the focal range and maintaining the optical performance seen in the 18-35mm 1.8 would be a challenge, more so than cost or size but Sigma will continue to push the boundaries on what lenses can do." The latter is certainly going to be interesting.

It is easy to overlook any focal length range deficiencies when getting an f/1.8 max aperture available over the entire focal length range. Not only is this the widest aperture zoom lens, but it is also the widest aperture 18mm lens. Full frame sensor camera owners have typically enjoyed about 1 stop of high ISO noise benefit and background blurring capability over APS-C/1.5x/1.6x format sensor camera owners. But, full frame camera owners do not have a zoom lens wider than f/2.8 available to them. The Sigma 18-35mm f/1.8 DC HSM "Art" Lens is a bit of an equalizer in this comparison.

While this lens is designed to cover only an APS-C-sized camera sensor, this lens mounts and functions on a full frame DSLR. And the vignetting is not as bad as you might expect. Here is a best-case example:

Check out the complete full frame comparison to get the entire picture.

I'm not ready to give up my full frame bodies, but ... I'm loving this lens. The great image quality seals the deal for the Sigma 18-35mm f/1.8 DC HSM Art Lens. The results that this lens is capable of delivering are impressive.