Published on December 7, 2020

Review: Sigma 100-400 DG DN for Sony E Mount

In the Sony E mount world, there aren’t very many options in the 100-400mm space. You basically have Sony’s own $2499 FE f/4.5-5.6 100-400 and this – the Sigma 100-400 DG DN. This alternative long range zoom is by all comparisons, an outright bargain at $949. But price isn’t always the be all end all. In this hyper competitive world of photography, are the tradeoffs one might find in the Sigma worth the monumental reduction in price? Alternatively, is the Sony 100-400 ~2.5x better?

While I don’t have a Sony 100-400 sitting around to do a direct comparison, I do have the Sigma on hand and have been using it for many weeks now. I feel that at the very least, I can speak to the strengths and the weaknesses of Sigma’s newer super zoom for the Sony E-mount range of cameras. Let’s get to it.

Specs & Hardware

Maximum Aperture: f/5 – f/6.3
- f/5: 100-113mm
- f/5.6: 113-235mm
- f/6.3: 235-400mm
Minimum Aperture: f/22 – f/29
Maximum Magnification: 0.24x
Minimum Focusing Distance: 44 inches (100mm) | 63 inches (400mm)
Optics: 22 Elements | 16 Groups
Diaphragm Blades: 9
Image Stabilization: yes (3 modes)
Dimensions: 3.39 x 7.76″ / 86 x 197.2 mm
Weight: 2.5 lb / 1135 g
Filter Thread: 67mm
Weather Sealing: Yes

I will admit, despite researching this lens a lot and watching a ton of videos / reading other reviews of this lens, I was still surprised when picking it up and taking it out of the box. It’s a big, meaty lens — and that’s before you extend it. Make no mistake, if you plan on doing any sort of on-the-ground / street photography with this, you’re not going to exactly blend in.

At 2.5lbs and mostly metal construction, there’s definitely a feeling of solidness and heft. It’s a well built lens that should take years of abuse and inclement weather. All of the buttons and toggles as well as rotating rings feel great and confident when using day to day. Weather sealing is present and after multiple trips into the rainy world, it performs just as good as the day I first got it.

On the barrel you’ll find several helpful hardware additions such as an auto-focus lock button, an auto-focus mode switch, a focus range switch, and an auto/manual focus switch. Additionally, there is a space for a lens collar and foot though it is an optional add-on purchase. While I would have loved for this to be included, it was also (probably) the only way Sigma kept this lens under $1k.

Performance

Below I’ll touch on the auto focus comparison between the more expensive Sony a bit more but for now let’s just say that it’s easily good enough. Coming from another lengthier zoom lens (the Tamron 28-200), I will say that the auto focus on this lens seems to be faster and hunt quite a bit less. That said, will more money get you more keepers? Sure. But for what this lens costs, I’m not at all upset with its hit rate.

One other small but potentially important difference to be aware of is macro shots. This isn’t exactly a macro lens. But…. if you are looking for some versatility in your ultra zoom, the Sony does maintain a closer focus distance throughout its entire zoom range whereas the Sigma will progressively grow from a decent 44″ on the 100mm end up to 63 inches on the 400mm end. Not great. Not terrible.

Value

These days, optics are often very close on the top competing “mid tier” lenses such as this Sigma when compared to their high end, first party counterparts like Sony’s own 100-400. One area of differentiation is typically build quality. For example, Some of the Tamron lenses I’ve used, while optically very good, are often simply less quality in terms of build materials and/or missing physical features (like additional buttons and switches on the lens itself). On paper, if the optics and build quality are so close to something like the Sony, what advantages does the Sony even have at this point?

Briefly — while the gap is closer than ever between top tier lenses and all the 3rd party lenses, there are still differences – better specs still and better build quality, even if minor, come to mind. Truth be told, we’re getting into the realm of diminishing returns.

Take for example, the aperture range. The Sony is a 4.5-5.6 whereas the Sigma is 5-6.3. There is a difference between these two make no mistake. And it could matter when all you need is just a 1/3 of a stop more. But at the end of the day, how often do you actually need that extra 1/3 of a stop to save an image? Do you need that extra 1/3 of a stop considering the price is another ~$1,500? Those types of scenarios keep cropping up. The buttons and switches and the Sony are similar in form and function and day to day, use as well.

Perhaps the only other big area of differentiation can be found in auto focus performance. My experience with the Sigma has been generally fine — that is, I have no complaints or major issues to report. But when compared to the likes of the Sony 100-400 side-by-side, the Sony appears to have better and more accurate auto focusing. For a lens in this range whose more common use cases revolve around wild life, this could be a crucial differentiator, and one that is well worth the extra $1500 alone. A handful of good commercial prints caught with this lens would easily make up the difference.

And that’s the crux of the issue. Are you a hobbyist or a professional? If the former, the Sigma is a much more approachable, perfectly usable lens. The Sony is that tool designed for the professional with the income to justify the overall minor but important differences. That said, if you fall into the camp that doesn’t want or can’t get the Sony and instead are looking at the Sigma, don’t for a second think you’re getting a measurably sub-par lens. You’re not. This is a great lens at $949.

Wrap-up

The asking price of $949 is insane for what you get here. Gone are the days when “budget” literally meant “slightly better than garbage”. In real world shooting, the Sigma is very competitive with the Sony and only when you find yourself in a small couple of scenarios (such as low light), does the Sony start to edge out the Sigma measurably. And even then, you’re not getting $1500 more worth of performance, quality, or lens. In many ways, the Sigma is the perfect buy. It does enough, well enough, that most people will be more than pleased. Count me in that group of people.

For the astute photographer who is looking to add to their portfolio with some unique looking shots that only a longer 100-400mm zoom can provide, this is a great entry point for Sony E mount shooters.

If you want to see some sample shots I’ve taken with this lens so far, I have a short video on my YouTube channel showing some off right over here. (Video also embedded below too.)