Sigma's 20mm f/1.4 Art Is Pure Heaven with No Competition (Unless You Shoot Nikon)

If you don't know Sigma's Art series lenses yet, you're missing out. Their well established 24mm, 35mm, 50mm, and zoom options in the Art lineup shine, but it's hard to believe it took this long for a wide-angle 20mm f/1.4 Art to make it out into the real world. But the moment I began shooting with this beauty is the moment of the past didn't matter anymore. We're in a new world: there's a 20mm to die for; and this is it.

Introduction

We've been very, very patient. Sigma had zero competition, so it's no real surprise that it took this long. Nikon's still-somewhat-new 20mm f/1.8G is a great alternative for Nikon shooters that does feature Nikon's excellent Nano Coating, but it's not as good as the 24mm f/1.8G (which is obviously not as wide) that just got rave review from DxOMark. Both lenses do fall over half a stop short of Sigma's sharp as hell, massively awesome 20mm f/1.4 Art. Thinking of Canon's EF 20mm f/2.8 USM? It may be cheap, but it's a full two stops tighter than the Sigma. And besides, it's so ugly. Just look at it...need I say more? Either way, it's the Nikon 24mm f/1.8G that we'll be considering as the only realistic alternative for Sigma's newest prime lens if image quality is a top concern.

The built-in hood does a great job of shielding the front element from sunlight and bumps alike. Overall, the lens has a great, solid, heavy feel to it.

If you're looking for the short version of this review, here it is: Just buy it -- especially if you're a Canon shooter. Then sell whatever you had before that was somewhat like it. On the other hand, if you're a Nikon shooter and don't absolutely need the f/1.4 aperture (most will find it hard to justify why you need that small difference), then you still have a decision to make. The Nikon is amazingly slightly cheaper, and beats the Sigma on sharpness and a number of other factors, even if just by a bit in both cases, and even if it's just DxOMark that currently says so. Nikon surprised us very pleasantly with their 24mm f/1.8G after their 24-70mm f/2.8E blunder. They may have a long-term chance against Sigma after all, as these are the kinds of results we've been waiting for. But back to this review of the Sigma...

First Impressions

This lens is packaged the same way as all of the other Sigma Art lenses: simply, but with everything you need (the lens and a case). Taking the lens out is when the real magic sets in. It's not small. Compared to the rest of the Sigma Art lineup, the 20mm is closer in size to the 50mm than it is to the 35mm and 24mm. This is in part due to its built-in hood that helps protect its bulbous front element, which brings us to our first and only real point of contention.

Because of its bulbous front element, the Sigma 20mm f/1.4 Art can't accept traditional screw-on filters. Much like Nikon's 14-24mm f/2.8 and Tamron's new-ish 15-30mm f/2.8 VC, you'll need a special, square filter kit like those made by Lee Filters in order to effect any change with polarizing filters, etc. At the same time, it's this feature that allows Sigma to deliver such a superb image. If I were a landscape photographer, I would have invested in an appropriate filter kit long ago anyway...

The Sigma 20mm f/1.4 Art is a very "good" size. The lens cap is a slip-on cover that slides firmly over the built-in leafed lens hood. Thankfully, it doesn't come off unintentionally.

If there's one reason to pay twice as much for more or less the same lens in the 24mm Canon L or Nikon f/1.4G version, it's autofocus (aside from the world of difference between 20mm and 24mm, of course). The Sigma Art lenses do extremely well, but the home-cooked variants tend to perform just slightly faster in my experience. Yes, it's almost imperceptible. But yes, "almost."

Thanks to the wide angle of the 20mm focal length, however, this difference is minimized and perhaps even negated altogether. Because wide-angle lenses have such relatively large depths of field, they don't have to "adjust" as much to get to a particular point of focus. This short throw means that focus is usually lightning-fast on wide-angles. Add to that the fact that this is a prime lens, and you've got focus speeds that won't leave your wanting more.

Either way, if you want proof of how good the Sigma is overall, it's time for our first sample image:

Apart from what you can tell from the general angle and some mild distortion of the circular saucer underneath the cappuccino cup, it's hard to believe you'd get this shallow depth of field from a 20mm lens. The bokeh looks like my 85mm shot at f/2 or so. Granted, this is way too shallow for this particular shot. But it does illustrate the point (just about the only in-focus point is the lip of the cup right where the drink spilled over slightly).

 

That right there is a JPEG saved straight from the raw .NEF file without any changes. 

In any case, if you never thought you'd say, "Bokehlicious," about a 20mm lens, think again. This has enough bokeh to smooth out the Eiffel Tower into an inflatable Air Dancer in the background of your street mime portrait series. In fact, I'm going to go order a second cappuccino right now... For anyone paying close attention: by "bokeh," I of course more accurately mean, "shallow depth of field."

With Nikon's f/1.8G (the 20mm and the 24mm), you still get a decent shallowness to the depth of field, or so I would imagine. I admittedly haven't had the chance to shoot with either yet, but physics is physics. And the cheaper price of either might still win your brain over, especially since we're probably talking about a relatively small perceivable difference in image quality between both of these lenses anyway. Then again, I'm sure you could still tell the difference in light transmission if you really need that extra (almost) stop. But those are all decisions you need to make.

The 20mm focal length is a refreshing one for walking around, as it brings a large section of life into the frame with relatively minimal distortion. I wish I had my tripod and a little more time on my hands to have made a real go of this shot as the clouds turned...(this shot is edited slightly).

Image Quality

I'm not a scientist. I'm not testing this in any special way. But when I take a look at these files taken with my relatively modest Nikon D750, I'm amazed. I've included plenty of samples (plain and not so plain) for you to mull over and form your own opinions. But contrast is punchy, color rendition is fantastic, and there's an air of sharpness surrounding every image in a way that makes me ooh and ahh over the results, regardless of whether or not I like the actual photograph in question.

You can't have a lens this wide without some noticeable distortion. And in the corners, it certainly is there. But if you're smart about shooting your wide-angle shots the way you should be by keeping recognizable objects or corners of clearly rectangular objects out of the corners, you'd be hard pressed to find any distortion that is too distracting.

That said, sharpness in the corners -- even on the edges as a whole -- degrades quite a bit due to just how wide this lens is. Honestly, it's a little more degraded around the edges than I would have expected. On the other hand, it's been a long time since I've shot anything decently wide at all. Although I may be out of touch with the "norm" for a wide-angle lens, everyone else seems to think it performs quite well. So for now, I'll chalk it up to an issue with this copy or perhaps simply an issue with my own perception of what is and is not normal.

You can take all of the "scientific" tests with a grain of salt, but it doesn't hurt that DxOMark and LensRentals like this lens, too. The new Sigma 20mm f/1.4 Art is sharper than the Nikon and Canon 24mm f/1.4 lenses in the center, and at least equal in corner resolution. That should set any last doubts at ease. Those interested in edge sharpness can enjoy the simple street shots below as examples.

This was shot at ISO 100 and f/2.8 just to get a feel for what would be considered a fairly medium depth of field for this lens. If you follow the in-focus area (roughly the middle of the road) to the edges of the frame, you'll notice some loss in sharpness...even continuing up to the trees on the left). Maybe the loss of sharpness in the edges is normal for a lens like this. While it's fine to my "normal" eye, it seems a bit less sharp than the pixel-peeper in me would prefer.
Here's one more shot where the softness in the edges is noticeable. Again, is this normal? You tell me... The rest of the frame looks fantastic, though.

Summary

I already mentioned the short version of this review above: buy this lens. But at the end of the day, we're lucky that one of our only options in the category is a fantastic one at that. The bulbous element should only disappoint the select few who constantly add and remove screw-on filters. And while there is no mention of an oil-, dirt-, and water-shedding fluorine coating like that on the front element of the Tamron 15-30mm VC (and Nikon's and Canon's super-telephotos), that's not a deal-breaker...it simply would have been a nice touch given how large the front element is. And it's not like these lenses are anything alike (though I still wouldn't blame your for having a tough time choosing between the two).

If you're a Nikon shooter, the 24mm f/1.8G offers just what this lens does and then some at a slightly more narrow field of view, except for the picky shooter's desire to get all the way to f/1.4. While I haven't shot with it yet, I would recommend trying it if it's an option for you -- you can even screw filters onto the front of that one.

As far as my needs go, consider them met. I'll be keeping this lens one way or another. Anyone want my 24mm f/1.4 Art?

 

The Sigma 20mm f/1.4 Art can be ordered in Sigma, Nikon, and Canon mounts for $849.00.

 

(Correction: This article originally made references to Nikon's 20mm and 24mm f/1.8G lenses in incorrect orders. These errors have now been fixed.)

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70 Comments

Lauchlan Toal's picture

The Nikon that's getting great reviews is the 24mm f1.8 - the 20mm f1.8 is also great, but not quite as excellent as the 24mm, by most accounts. The 20mm is also significantly older than the 24mm. Other than that, nice review. Sigma is definitely on a roll with their fast wides, it'll be interesting to see how their telephoto primes hold up.

Eric Duminil's picture

"The 20mm is also significantly older than the 24mm."
I lol'ed. You mean, like 11 months?

Lauchlan Toal's picture

Yep, 'bout that. Very popular astro lens since its release.

Adam Ottke's picture

Thanks for the note. I had the 24mm and 20mm mixed up in a few spots where I meant to say the other... Got my head screwed on right this time since the most recent edit, I hope. Cheers.

Lauchlan Toal's picture

No problem, easy to get the two mixed up when tabbing between product pages. Bonus points for the Sigma, being wider and faster than the 24mm f1.8 which recently was lauded by Dxomark in any case.

Patrick Hall's picture

I feel like these ultra wide primes with fast apertures are primarily aimed towards astrophotography and photographing the night sky. Did you do any tests with it at night with long exposures?

Tony Hoffer's picture

We shot some night stuff with ours and used it a ton in this post: http://hofferphotography.com/2015/12/08/teryn-randy-at-the-loft-in-bloom...

Patrick Hall's picture

Those are seriously some awesome wedding photos Tony! I'm super impressed. How did you do the makeup shot? Was that a multiple exposure or some sort of prism?

Adam Ottke's picture

Agreed. Seriously, these are awesome.

Tony Hoffer's picture

Thanks! Patrick, the makeup photo was just with some mirrors that were sitting around. I have long fingers :)

Joe Schmitt's picture

Damn, Tony. Just...wow. Stellar work. I will be looking at your photos for some inspiration. Absolutely beautiful.

Eric Duminil's picture

Holy shit, you're good!
Almost all of them would have 5 stars in my library.
Very nice job, and I bet your clients are super happy.
Congrats.

Tony Hoffer's picture

Thanks!

Alan Johnson's picture

Tony, are you shooting the Nikon 24 ,20 or the Sigma? Very expressive photos.

Tony Hoffer's picture

Hey Alan, we have a ton of lenses but the Sigma 20 was used hard at this wedding. We just got it in last week.

Alan Johnson's picture

Thanks, I am heading to Mpls today, I will have to stop and take a look at one. Haven't bought a non Nikkor lens in a long time. Will have to see how it feels.

Alfred Wilmot's picture

thanks to your wedding pics, I bought the SIgma 20mm. Thanks again for sharing those pictures with us

Matei Botan's picture

I really love your style...very fresh...best wedding photography I've seen in a while

Tony Hoffer's picture

Very kind of you. Thanks!

Bentley Crawford's picture

Tony, very nice! Were the majority of those shot with the 20 1.4? Would you recommend this as a great event lens in addition to landscape?

Tony Hoffer's picture

A bunch of them were... Especially the reception stuff. I haven't used it for landscapes except for a few at night. The cover photo on that post is one of them. It blew me away at night.

Aaron Hill's picture

Absolutely incredible shots! First time making a comment on Fstoppers, had to go out of my way for this post.

J H's picture

Very impressive images Tony!

Gilbert de Leeuw's picture

Amazing pictures Tony.May I ask you did you borrow this lens for the wedding? Would you hold on to it for future weddings after your experience with it? I'm looking for a wider prime ... I shoot mostly weddings exclusively with primes and well I need something wider than 35. I was going to grab a 24 1.4 until this lens came around now I can't make up my mind. Thanks!

Adam Ottke's picture

Thanks for sharing, Tony. Patrick, unfortunately this lens only made it to me a few days after my awesome astrophotography shoot recently at Mt. Wilson. And it's been cloudy with more crappy weather every since. But if I have the chance before I send the lens back, I'll work on getting some of those test shots in myself in a future update.

Joel Meaders's picture

WOW! Your shots are astounding.

Bill Peppas's picture

Indeed Patrick, their ideal use would be astrophotography ( and landscapes if you're very serious about it going full focus stacking )

Caleb Kerr's picture

I'm considering trading out my Tokina 16-28 f/2.8 for this. I only ever use it at 16mm and would prefer a prime. 20mm is a just slightly tighter than I would choose but I love that it has barely any distortion and I think that's a worthy trade-off for the prime and the f/1.4.

Adam Ottke's picture

I think you're spot on with your thinking. Any prime, in theory, has plenty of potential to be better than a zoom -- especially when considering a Sigma Art-series prime against a Tokina zoom. I think you'd be very happy with the trade. Continue shooting at f/2.8 if you want to for ultra-sharp images. And then have the flexibility of shooting at f/1.4 or f/2 with very little trade-off. I've switched my entire kit to primes (Sigma Art primes plus the Nikon 85mm f/1.4G), except for my 70-200mm f/2.8 VR II which is just too useful at times to give up (although I still might, as I'm shooting events less and less these days...and even then I can get away with the primes). Hope that helps...

Caleb Kerr's picture

The impracticality of using exclusively primes doesn't outweigh the convenience of quality zooms for me overall, but I do love my primes additionally... like the Canon 135mm f/2L.

Adam Ottke's picture

It is more impractical in some cases, sure... But it also depends largely on what you shoot and what you need really. If I shot weddings for a living, I'd keep all my zooms. But most of what I do...well...I'm fine with primes :-)

Ariel Martini's picture

i'd like to see depth of field and sharpness comparison with nikon 20 1.8 @ 1.4 and 1.8

alexis vander linden's picture

searching for a comparison too

Jason Ranalli's picture

Great read even though I'm not into wide angle lenses that much.

I must say though that the shot in cafe with the coffee might change my mind on needing such a lens. I would have never of guessed that you can get such nice bokeh/DOF with a 20 mm lens. I honestly haven't tried but I don't think I could get that with my Nikon 14-24 2.8.

Tony Hoffer's picture

I'm new here so I don't know if you can see my avatar any bigger, but I took it with the Sigma 20 at 1.4 in our studio. Gives you a sense of the bokeh.

Jason Ranalli's picture

Thanks Tony...I saw your wedding pictures as well....they are truly fantastic!!

You're also in Downingtown? I just moved to the Paoli area a few months back :)

Juan Osorio's picture

Huge 1.4mm aperture and huge field of view; almost a fisheye lens. The main reason is lens is so exciting is because it captures light faster than any other lens with this aperture. This will be the best astrophotography lens as long as it doesn't have comma aberration. I have looked everywhere and I haven't been able to find a review that addresses this very important issue. Please, if anyone knows the answer, share the information and/or link.

Adam Ottke's picture

Chromatic aberration is VERY well controlled. I had a hard time noticing any. Usually, those leaves on the tree might suffer around the edges where the sun comes through behind them. It's hard to see in the small version there, but there's none to speak of...

Juan Osorio's picture

I am sure chromatic aberration is not an issue. Comma aberration is a problem that can only be appreciated when you shoot astrophotography. Even lenses with well controlled chromatic aberration can have different degrees of comma aberration. Perhaps this link will shed some light about the issue:
http://www.lonelyspeck.com/a-practical-guide-to-lens-aberrations-and-the...

Chromatic aberration can be corrected with Lightroom or Adobe Camera RAW. Coma aberration cannot. It can be fixed in Photoshop through a very time-consuming process. See Youtube video:
https://www.youtube.com/watch?v=YuEX3KLrAUo

Still, it would be fantastic if somebody share pictures of stars with the new Sigma 20 mm 1.4

Adam Ottke's picture

Okay, okay. We're supposed to FINALLY have a clear night this weekend. I'll hold onto the lens and do my best to get some nice test shots for you guys under a night sky. Stand by...

Juan Osorio's picture

You will be the first to review this awesome lens in terms of coma. If you also post a video on YouTube it will receive hundreds of thousands of views since this is perhaps the most anticipated lens for astrophotography provided coma is controlled.

Adam Ottke's picture

I'll do that. And sorry! On mobile and read a bit too fast. Yes, I'll watch for coma aberration especially. Will get back to you (fingers crossed for great weather when it's supposed to be here!).

Juan Osorio's picture

Please test the lens fully open at 1.4 and then close it one stop at a time with the same image. This article discusses why the Rokinon 24mm 1.4 has been so far the king of astrophotography, even better than the most expensive Canon or Nikon lenses. The key is the stellar performance at the most desired bigger apertures.

http://www.lonelyspeck.com/rokinon-24mm-f1-4-ed-as-umc-review/

Hope you will find it interesting.

Larissa J's picture

How did the weather treat you over the weekend? Did you manage to get any astro shots? I've read a few reviews that mention issues with vignetting, so I'm keen to hear about that and how it performs coma wise.

Adam Ottke's picture

Thanks for asking. I did try, but the clouds just wouldn't clear up over me at night (and I drove a ways, too). One night it just wouldn't stop pouring, even. I have decided I will keep the lens until I get this answered for you guys, though. I'll intend to make a short post just on the lens' astrophotography performance if that helps. So stay tuned!

Larissa J's picture

Thank you, it's much appreciated. I'll keep an eye out :)

Adam Ottke's picture

Weather says it's clear!!!! I'm headed out! Man... Hope this works!

pat laskowski's picture

Just ordered mine from Adorama - nice little bundle for for $849. Price of just the lens - $899. I'll give the software and cleaning kit to my 16 yo grandson who is getting into photography with my hand-me-down Canon T2i and Tamron 18-270 lens.

Juan Mojica's picture

how would you compare this to the 18-35mm sigma art lens? Would this be any benefit over that? (On a crop frame sensor that is)

Adam Ottke's picture

While the inherent quality might be better with this lens, it's hard to justify getting it for an APS-C body since you'll lose your wide angle of view (20mm here will act like 30mm on that crop sensor). I think you're better off with the 18-35mm in this case, but that also depends largely on what you're shooting. Sigma doesn't currently give you too many great options specifically for crop sensors as they do for full-frame setups...

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