Decent but Flawed: We Review The Sigma 100-400mm f/5-6.3 DG DN OS Contemporary Lens for Fujifilm X

Decent but Flawed: We Review The Sigma 100-400mm f/5-6.3 DG DN OS Contemporary Lens for Fujifilm X

The zoom telephoto lens pool for Fujifilm X mount is growing larger each year, and that can only be a good thing. Fujifilm already offers multiple great candidates. Tamron and Sigma are also getting involved as they too want a piece of the pie. Do they stack up? The Tamron 150-500mm certainly does, but how about the Sigma? Let’s have a look!

Decently Built

I’ve been given a solid number of Sigma lenses to test out over the years. More often than not, I am delighted with them, as they offer a really nice blend of decent image quality and a very manageable price tag. I’ve been known to praise the recently released f/1.4 DC DN primes for their very competitive image properties, compact sizes, and more than affordable price range. The latest piece of glass, however, leaves me rather stumped. I can’t quite recommend it to most users, but I can’t truly discourage anyone from getting it either. It does have merits, but it does come with some, for me at least, pretty unfortunate flaws.

Let’s get the basics out of the way first, though. The Sigma 100-400mm f/5-6.3 DG DN OS Contemporary lens is mostly comparable to the Fujifilm XF 100-400mm f/4.5-5.6 R LM OIS WR. The price of the Sigma is currently roughly $1,000 less than the Fujifilm, not taking time-limited deals into account, and it does save on both the size and weight, but it does so at the cost of a smaller aperture and a lack of few features. The body of the lens measures less than 20 centimeters in length and weighs a little over a kilogram. That is less than eight inches and just around three pounds for my American friends. Not too big, not too heavy.

Sigma 100-400mm f/5-6.3 DG DN OS Contemporary

I’m pretty sure the outer materials used play a role in that. Yes, the lens is plastic on the outside but still fairly sturdy and seemingly built well. On the outside, it does seem weather-resistant, but I could not find any official confirmation of such a feature apart from the mount having a rubber gasket, which Sigma even mentions on their website. No word on the rest of the lens being sealed, though. Something tells me it unofficially is, but it's not claimed anywhere in writing to prevent any legal issues from misuse. 

The design is fairly simple yet not boring. The barrel is dominated by a few standout features. First is a rubberized large counter-clockwise zoom ring with a just-right travel length. All you need is a quarter twist to get from the widest 100mm to the longest 400mm. I certainly welcome not having to twist my hand all around the lens to utilize it fully. This is not the only way to change your focal length, though. You can also just grab the hood on the back section and simply pull it to zoom. This can speed up your tracking significantly and is officially supported by Sigma, so no need to worry about ruining the lens.

Sigma 100-400mm f/5-6.3 DG DN OS Contemporary

The plastic focusing ring is unassuming, and to be fair, it will most likely never see use from the majority of its owners. The lack of an aperture ring is unfortunate but expected when it comes to X-mount Sigma glass. It shouldn’t be much of a downside to most Fujifilm shooters, but X-H2(S) owners have to take into account that if they work in manual mode they now need to switch between aperture and ISO on one of their control wheels as those cameras only offer two wheels.

We can attach a tripod collar, but it is not included in the box by default. The mounting point is covered by a removable rubber ring. Last but not least are the controls on the left side of the barrel. We get the traditional stabilizer switch with two separate modes, a very welcome focus distance limiter, and a button that can either work as your AF button or an AF-L one. We also get a zoom lock incorporated into the zoom ring to avoid creeping of the front element when traveling, as the lens does extrude when zooming in.

Sigma 100-400mm f/5-6.3 DG DN OS Contemporary

How About the Internals?

The aperture mechanism consists of nine rounded blades, same as the more premium Fujifilm XF lens. However, the Sigma does firstly focus closer at 1.1 meters (3.61‘) compared to Fujifilm’s 1.75m (5.74'). The magnification is also slightly better at 0.24x compared to 0.19x of the Fujifilm counterpart. The focusing group is driven by a silent and fairly quick stepping motor, which is neither a disadvantage nor an advantage over the linear motor of the XF 100-400. I’d like to say that the focus was fast and accurate, but this is where the first issues arise. Yes, the lens did focus fast, or at least it confirmed an accurate acquisition quickly. But on an occasion here and there, the final image just was not in focus when viewed up close. I can’t with 100% certainty say whether it's focus or optical quality, though.

It shouldn’t be an issue. We’re using a full frame-capable lens on an APS-C body, ignoring the weakest spots of any glass, the corners, and utilizing only the sharp center of the image circle. And more often than not, I was getting tack-sharp captures on my X-T5 with its 40-megapixel X-Trans 5 HR sensor. But that was mostly when I used any other focal length apart from the shortest and longest. If I took a shot at a random length like 174mm, or 265mm, the image came out perfect. But once I shot the image at either 100mm or 400mm around half of my images just weren’t as sharp as I’d like them to be. It most likely wasn’t a focusing issue from what I’ve tested. I’ve used single AF, continuous tracking, and face detection, and the results were the same. But as I’ve said before, I wouldn’t bet any money on who is the culprit. It could’ve been just the unit I was using as there are other reviews out there that never mentioned any such issues, but I’d be lying if I omitted it from this article. 

Sigma 100-400mm f/5-6.3 DG DN OS Contemporary

Ignoring the few soft images I got, the sharp ones were definitely worth keeping. The definition was good enough for the high-resolution sensor of my camera, the colors and contrast were captured rather nicely, and I was more than satisfied with the way Sigma handled chromatic aberrations and LoCA. Even the bokeh was lovely and smooth thanks to the 9-bladed rounded diaphragm. The separation of the subject from the foreground and the background is clear and pleasing.

What I Liked

  • Manageable weight
  • Short zoom ring travel
  • Pull/push to zoom feature
  • Image stabilization
  • Focus limiter
  • Relatively compact size
  • Fast stepping motor

What I Disliked

  • Occasional soft image
  • Lack of aperture ring
  • Not officially weather-sealed

Would I buy it?

It is not an easy call. The size and weight of the Sigma 100-400mm f/5-6.3 DG DN OS Contemporary both make it a very comfortable piece of gear to carry around even on a smaller body such as the X-T5. The fast zoom makes it great for shooting quickly moving subjects and the build including the controls makes the lens feel high quality. Optically it also performed well, when it performed. But the occasional soft image made me cautious of my focal length. I had to make sure to not use the extreme ends of the focal range to get the best out of the lens which is not something I’d like to have to constantly think about when shooting. I’d most definitely recommend testing the lens thoroughly to see if it's a good fit for you. I will most likely try using a different unit to see if my worries are unfounded and if it turns out to be true, I’ll let you know in this article or the comments. 

Speaking of the comments, do you own the lens? Have you used it? How satisfied are you with the image quality?


Ondřej Vachek's picture

Ondřej Vachek is a Prague based independent documentary photographer and photojournalist with multiple journeys to war-torn Ukraine where he covered everything from the frontline in the Donbass to the civilian life adapting to the new normal. Avid street photographer with love for writing and storytelling.

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Strange? You're the first reviewer who had bad images. Before buying mine, I went to see reviewers around the web. The Aperture ring that you miss is a FUJI thing. All new lenses from third parties won't have it. Not officially water sealed is right, not everyone needs it. Soft images can be a result of any factors including bad lens sample or bad handling of the camera. I hope that reviewers look at other reviews to see if their review could be wrong. Since you're being paid to make reviews, try to make it pro one.

I think the review was quite balanced, it pointed out more than once any shortcomings could have been caused by this particular sample or other factors. And, quite frankly, I prefer reviews that don't compare themselves to others. I'm not reading reviews to find me-too outcomes, if the line does have sample variation that too is useful information.

A fellow writer has also reviewed the lens a while back so I asked him for some crops of his images and the results were unfortunately very much aligned with what I've shot with the unit I was using. I can still imagine using such lens, just not on the 40-megapixel sensor.

I feel you're taking the review a tad personally. If you're satisfied with the lens I'm happy for you. An aperture ring is not a Fujifilm thing only anymore. Sigma does it, Sony does it, Viltrox does it. I use it regularly so I miss having it. Simple as that.
Sure, not everyone needs weather sealing. I do so I stated is as a negative from my point of view. If you don't need it simply disregard my point. You're free to do so.
As I've said in my response to Stu. I've since looked at images from different units with similar softness when zoomed in. I wouldn't mind using the lens on the lower-resolution sensors of last generation Fujifilm bodies but not on the 40-megapixel 5th gen. I can assure you it wasn't a camera handling issue.

Yes I most admis that I was surprised and shocked. Like everyone I went to see every review. I could have bought the FUJI ones, but at twice the price (even on special). Most reviewers said that in some cases the FUJI are better but taking into account that most people won't notice it, it's not worth paying. I used to have FUJI lens, but their weight is getting causing problems for transportation. TAMRON and SIGMA build their lens for many camera manufacturer so they can make them cheaper, if I can say that.

The Tamron 150-500 is great, but a bit on the large and heavy side. The Fujifilm 70-300 is pretty light, fast, and small. The Fujifilm 150-600 is long, but surprisingly light as well if you're ok with the f/8 aperture on the long end. In terms of sharpness, all of these outperformed the Sigma in my testing.

I think people will be a bit critical due to the praise this lens gets. Most people who review this lens don’t aim for a 400mm away subject and often focus on something in-between. If you see a bird 200 ft away and snap a photo, it’ll be sharp at 400mm. If you take a photo of a bird 1000 ft away at 400mm, itll be slightly blurry regardless to humidity and air quality. The lens simply farther focal distances for sharpness is around 5. The lens also isn’t a fan of Dynamic range modes enabled. While it’s good at tracking from certain distances, it simply can’t keep up with Fuji’s variant for a few bucks more. It can be a bit picky with the aperture at certain distances. There’s noticeable fringing at certain distances regardless to aperture and with any light going into the lens (including reflections) you’ll end up with a soft image. These issues are obviously with both handheld and tripod mode. At times you have more luck turning off continuous auto focus and even manually pulling focus.

With that said, it’s not a bad lens. If you’re a budget lens owner in general you may even be surprised and love the results compared to your other lenses. But if you’re used to using $1500-$4,000 zoom lenses you’ll instantly notice the lack of quality of images you’ll end up with. Your back needs to be facing the sun at all times and this lens is only workable from noon till before sunrise. Once you start lifting the iso you’ll only find your zoom in 400mm a grainy mess with little to no details.

This lens gets good reviews as a budget lens. Any review of this lens against fujis two infamous zooms including the 600mm… this sigma lens falls short. Other reviewers use it for more close up objects, subjects and animals and don’t attempt to focus on something 300-400mm away. And like I stated.. it also depends on the time of day you’re shooting. Most good lenses can handle a bit of direct light and reflections. This line can’t handle even the slightest bit.

I’ve rented this lens many times before buying it. I’ve had my hands on maybe 14 different variants of the lens. For me it’s a great travel lens or going to get some photos of birds / animals lens. It’s light and fits in my camera back and doesn’t break your bag when strapped around your neck on your camera. It beats pulling out a tripod and being stuck in one spot for a few hours hoping something comes between you and your lens. But it’s def a flawed lens.

As a budget lens I’d give it an 8.5
As a professional lens.. 3.0