Sigma 20mm F2 DG DN Contemporary Lens Review

Sigma 20mm F2 DG DN Contemporary Lens Review:

Sigma has really been creating great gear for L mount users, and it looks like they’re not ready to stop any time soon.  For instance, if you’re looking for a wide angle lens, they already have a 24mm f2, and a 24mm f3.5, both with the I Series designation, which means designs that not only include exceptional optics but are much more manageable in terms of size.  If you’re looking for something a bit wider than a 24mm, you’re in luck because as of today, they have just released the 20mm f2 DG DN Contemporary lens, and thanks to Sigma, I was able to test it out before hand.  Here is my full review of it.

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Sigma 20mm F2 DG DN Contemporary Lens Build Quality:

Let’s first start off by taking a look at the overall build quality, which I have to say is excellent.  The new 20mm f2 is a lens with the I Series designation, which Sigma points out is not a product line like Art, Sports and Contemporary but kind of like a nickname that represents a set of lenses with similar construction.  In this case, you’re getting lenses that are not only exceptional optically but are also compact and light.  Aesthetically, the designs are really nice as well.

↑ Here’s the Panasonic S5 with the new Sigma 20mm f2 DG DN Contemporary lens attached.

Often times, lenses with a larger maximum aperture are heavier or less manageable in terms of weight and size.  It kind of comes with the territory, if you want something with more light gathering capability but with that said, Sigma did a great job trimming the bulk off the 20mm f2.  For instance, the weight is just 370 g/13.1oz., and the dimensions are 70mm×72.4mm /2.8in. x 2.9in.  It also has a 62mm filter thread, and if you look at the dimensions of the 24mm f2 DG DN Contemporary, you’ll notice that both these lenses are very similar in size (you can read my 24mm f2 review here).  This all means that the 20mm f2 is a lens that can definitely be used all day long without feeling fatigue.  This, to me, is particularly important considering what many might use a wide angle for in terms of shooting. 

Because of its focal length, many will probably use this lens for travel, street photography and landscape, just to name a few, all of which often requires one to trek around quite a bit.  You want something light, something easy to carry around, and something that just really isn’t going to get in the way.  You also want something that isn’t going to draw too much attention, especially for street photography.  You get all of this with the new 20mm but also the versatility of having a wide open aperture of f2, which means that if it gets darker out there, you still have the ability to shoot without boosting your ISO to crazy levels.  I’m a bit old school, and while cameras these days can perform quite well at higher ISO, I always try to shoot at the lowest setting possible for better image quality.  I tested this lens quite a bit with the Panasonic S5.  As some of you know, the S5 is very compact, and therefore, it matched perfectly with the lens.

↑ Here’s a top view.

Besides its fantastic ergonomics, the 20mm f2 DG DN Contemporary lens is definitely a high quality lens in terms of the way it’s made.  It feels extremely solid in the hands.  Like the rest of the I Series, the 20mm f2 has an all-metal body with high precision internal parts that are also made of metal.  There is an aperture ring, which clicks solidly in third stops as you rotate it.  I have to say, I love my Leica SL lenses but I really do miss having an aperture ring, and therefore, it’s great to see one on the 20mm f2.  There’s also a focus ring that is smooth in operation, and both rings have knurled surfaces which provide great tactile feel even when conditions get a bit wet outside.  There’s also a brass bayonet mount, which has rubber sealing for dust and weather resistance.  Lastly, there’s a newly designed arc-type auto/manual focus switch, and while I only tested the L mount version of this lens, I’m happy to report that it also comes in Sony E mount.

There are also several accessories included like a metal knurled lens hood that is a simple twist on locking type.  It matches the lens extremely well in terms of size and appearance.  Two lens caps are also included.  One is a plastic snap on type that typically come with most lenses out there these days, while the other is a magnetic metal lens cap.  The metal lens cap is quite cool, and I love how it simply sticks on to the front of the lens.  It’s also felt lined on the inside part, so it won’t mark up your lens when it is attached.  You can also purchase the Sigma CH-11 Magnetic Cap Holder, which has a carabiner to clip to things like your bag or belt loop.

↑ The 20mm f2 DG DN Contemporary lens comes with a metal lens hood, plastic lens cap, and a magnetic metal lens cap.

↑ Here’s the magnetic lens cap attached to the lens.

Sigma 20mm F2 DG DN Contemporary Lens Autofocus:

As for autofocus, the 20mm f2 DG DN Contemporary lens uses an STM motor that I found to be fast, accurate, and silent.  I’ve been testing the 20mm f2 quite a bit in all types of environments and conditions.  I was out during sunny days and even cloudy, rainy days.  I also tested this lens indoors and out.  I found the autofocus performance to be excellent with no drama whatsoever.  The autofocus is efficient, and it’s good enough that it’s not even something I think about while I am shooting.

I also did try this lens with face detection, and I’m happy to report that I didn’t experience any real issues having the system find a face, and locking on every time.  With Covid cases so high in New York City or much higher at the time when I was testing this lens, I had to cancel my model shoots but I did try some candids on the street.  Overall, I’m betting most will be quite happy with the autofocus performance.

Sigma 20mm F2 DG DN Contemporary Lens Image Quality:

Quick note about the images: Covid cases were very high in NYC when I was testing this lena, so I kept my picture taking down to a minimum.  There are less pics (and variety) than what I would normally post for a review.  Still, there are plenty of pics that will show what this lens can do.

In addition to all of what I just said, the optics are also fantastic.  It’s worth noting that Sigma even says their f2 I Series lenses, like the 20mm in this review, have comparable MTF charts in terms of optical performance to their f1.4 Art lenses, which as some of you know, are some of Sigma’s best performing lenses.

↑ This was taken using f5.6 and 640 ISO.

↑ Here’s a photo taken with f8 and 200 ISO.

↑ I used f8 and 160 ISO here to take this photo.

Let’s take a look at sharpness right now, and as you can see from the images, it clearly scores quite high in this category.  While I did not do a direct comparison with the 24mm f2, since I did not have that lens here with me at the time, I found the two performed very similarly, which is a great thing because I was quite impressed with the 24mm f2 (review here).  At wide open aperture, the 20mm f2 is also razor sharp in the center with edges and corners nearly as sharp.  Stopping down sharpens up the image just a bit but overall, you should be able to produce excellent results throughout the aperture range.  The images are just so crisp and detailed.  There’s really a nice three dimensional pop to photos as well.

↑ I took this using f4 and 400 ISO.

↑ Here’s a photo taken with f8 and 160 ISO.

↑ Here’s a 100% crop of the photo above.

↑ Here’s a photo I took early in the morning with the settings being f8 and 320 ISO.

↑ Here’s a 100% crop of the photo above.

Of course, there are other characteristics that really make this lens stand out optically, such as it’s color and contrast rendering.  There is some vignetting at f2, which is not out of the ordinary.  However, stopping the lens down by just one stop significantly reduces the vignetting.  As for flare, I found it to be highly resistant to it in normal use.  Overall, there really isn’t much to complain about here.  As some of you know, I don’t test gear on a scientific test bench or anything.  I use the gear in the real world, and I truly found this 20mm f2 to be quite exceptional, and up to any task you can throw at it.

↑ Here’s a photo I took while in Zuccotti Park.  The settings are f8 and 1250 ISO.

↑ This was taken on my walk back to my studio space.  The settings were f8 and 320 ISO.

↑ This was taken in the Oculus with the settings being f4 and 1250 ISO.

Sigma 20mm F2 DG DN Contemporary Lens Bokeh:

As for bokeh, it is very smooth, and inviting thanks in part to its 9-blade rounded diaphragm.  I feel Sigma lenses do a great job when it comes to bokeh, and this lens is definitely no exception.  However, achieving a thin depth of field to see the bokeh more clearly isn’t always easy, which is no fault of the lens, of course.  This is an ultra wide angle, so in general, you would have to get quite close to really notice a significant shallow depth of field.  The f2 here, like with other fast ultra wide angle lenses, is really more for being able to shoot in dimly lit situations, at least for me.

↑ Here is a photo taken with f2 and 100 ISO.

↑ Here’s a 100% crop of the photo above.

↑ Here’s another example taken with f2.  I used 250 ISO.

↑ Here’s one more taken with f2 and 100 ISO.

Pros And Cons:

Pros:

• Excellent build.
• Metal lens hood.
• Magnetic lens cap (in addition to the snap on lens cap).
• Great ergonomics; compact and light.  Similar in size to the Sigma 24mm f2.
• Great autofocus.
• Superb image quality.
• Decent bokeh when you can achieve it.
• Great price.

Cons:

• Not much to be honest.  I feel you’re getting an excellent package here…maybe lack of image stabilization but it’s not needed in my opinion.

Sigma 20mm F2 DG DN Contemporary Lens Verdict:

As some of you know, I’ve been an L mount user since the Leica SL, and I feel optics like this 20mm f2 DG DN Contemporary lens are what we definitely need more of to make the L Mount Alliance a better system.  All in all, the 20mm f2 is another fantastic lens to come out from Sigma, and another great addition to the L Mount Alliance.  To me, it ticks off all the right boxes for an ultra wide angle.  The ergonomics are pretty much perfect, build is excellent, the autofocus is fast, and of course, the image quality is impressive.  On top of all that, you have a large f2 maximum aperture making this lens very versatile, and great for all types of situations.  Achieving all of this, especially for the right asking price of $699, is not easy for any manufacturer, so I give Sigma a lot of credit here.

↑ This was taken inside the Oculus.  The settings were f4 and 320 ISO.

↑ This was taken inside the Fulton Street Station.  The settings were f4 and 6400 ISO.

↑ Here’s a photo I took while walking on the High Line in Chelsea.  The settings were f5.6 and 2000 ISO.

Like the Sigma 24mm f3.5 (review here), and the 24mm f2 (review here), I feel the 20mm f2 helps make the L Mount Alliance more complete because let’s be honest, there aren’t a ton of ultra wide angle lens choices in the L mount system, especially if you want autofocus and/or you don’t want to use an adapter.  For the type of photos I take, I don’t always need an ultra wide angle lens but after using this one, even I’m tempted to get a copy.  It’s really something just so nice to have, even if you’re like me, and would only use it for certain situations.  You’re really getting one of those types of lenses that, that in my opinion, is the total package because it is so well-rounded.

↑ Here’s a photo inside the Oculus that I took with the settings being f4 and 640 ISO.

↑ Here’s a photo taken outside the Oculus with the settings being f8 and 400 ISO.

↑ The last photo here was taken with the settings being f8 and 320 ISO.

↑ Here’s one last photo of the Sigma 20mm f2 DG DN Contemporary lens.

So, if you’re looking for an ultra wide angle lens, I highly recommend you put this one on your list to consider.  It really has a lot to offer, and it’ll help you produce some stellar photos.  As always, thanks for stopping by!

Thanks for taking the time to read my review!  If you’re considering purchasing the Sigma 20mm f2, and my review helped you decide, please help support this site by purchasing from the links below or any mentioned in this review.  It will not cost you anything extra. Thank you for your support!

Sigma 20mm f2 DG DN Contemporary lens at B&H Photo