# TDP posts full image compare for Sigma 20mm ART. Better than new Canon 24mm?



## ScottyP (Dec 4, 2015)

The 20 surprisingly whips the 24mm in vignetting wide open.

http://www.the-digital-picture.com/News/News-Post.aspx?News=17262

It also seems sharper in center and middle and seemingly has less CA.

(edited to properly insert the hyperlink)


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## ahsanford (Dec 4, 2015)

*Sigma Art 20mm:*

Clearly sharper, especially on the wide open end (LensTip believes the 24L II is sharper in the center when stopped down, but TDP's sample disagree with that)

Less vignetting

Slightly better coma wide open for astro (see at LensTip here and here), but neither truly excel here

Greater ability to tune the AF on the Sigma USB Dock than with AFMA


*Canon 24L II:*

Weather sealed

More _consistent_ AF (not thoroughly proven yet, but assumed based on the Sigma 35 & 50 Art AF performances)

Better build quality (Presuming again -- I've shot the 35 Art and 24 L II, but not the 20 Art, I'm assuming it's similarly 'Art-Like'

Presumably better resale value 


Personally? For me, the wider these Art lenses get, the less I need AF with them. At 35mm, the AF has got to be there for what I shoot, so I passed on the Art due to too many misses shooting wider than f/2 --> I'd get the 35 f/2 IS USM or 35L II depending on your budgets and needs.

But down around 20-24mm, perhaps an occasionally inconsistent AF won't kill you and the comically good value proposition of a super sharp 20mm prime is worth it. And let's face it, unlike Canon with two very good 35 primes, at 20mm Canon forces you to pricey and not a sharp primes in the 17-24 neighborhood (some lacking AF altogether) or forces you to a zoom. So hats off to Sigma for swinging for the fences here.

_...except for astro folks_, who may have thrown this lens out of consideration solely for coma reasons. 

- A


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## TeT (Dec 4, 2015)

Someone finally made a sharp 20mm 1.4 AF...

The lens to compare it to is not the Canon 24 but the Sigma 24 Art. Why were they able to get this one sharp at 1.4 but not the Sigma 24 ...?


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## Talley (Dec 23, 2015)

TeT said:


> Someone finally made a sharp 20mm 1.4 AF...
> 
> The lens to compare it to is not the Canon 24 but the Sigma 24 Art. Why were they able to get this one sharp at 1.4 but not the Sigma 24 ...?



uh... the 24 is sharp. I have right now the 24A and 50A and had the 35A and they are all equal in performance.


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## JohnDizzo15 (Dec 28, 2015)

Just got my copy this morning. It is fantastically sharp from my initial playing around. Adapted and mounted on a Sony though since I no longer have a Canon DSLR.


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## Mt Spokane Photography (Dec 28, 2015)

I am wondering just which new Canon 24mm Lens the title refers to? I'm not aware of any new one, the 24mm f/1.4 MK II is getting a bit old now, it came out in 2008 seven years ago.


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## JohnDizzo15 (Dec 28, 2015)

It's a beaut. 

And at Spokane, I thought that was weird too that they called it new.


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## Larsskv (Dec 28, 2015)

TeT said:


> Someone finally made a sharp 20mm 1.4 AF...
> 
> The lens to compare it to is not the Canon 24 but the Sigma 24 Art. Why were they able to get this one sharp at 1.4 but not the Sigma 24 ...?



I guess it's the extra 300 grams...

I'm going north to see the northern lights in two days, and picked up the Sigma 20 f/1.4 today, to be best prepared. I'm very excited. 

First impressions are very good. I spent two minutes AF adjusting it on my 5Ds, and focus accuracy now seems to be very good. DOF is wide, so I didnt really expect any larger issues either. Sharpness is amazing in the center even at f1.4. Corners could be better at f1.4, but they are acceptable to my standards, and seems a fair bit better than the corners I got from a 24LII I tried some time ago. Vignetting yes, but the transmission is smoth. 

It is heavy, but it's a speciality lens, so I am quite forgiving about that.


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## Busted Knuckles (Dec 29, 2015)

WOW! I just walked through the vignetting, and MTF comparing the 20 art vs. 24L II. On the 5d R It is simply not a contest.

At 1.4 the corners are a bit interesting and perhaps debatable, but at f 5.6 WOW! 

As you would expect the 24 handles distortion better than the 20.

I very much like by 24 and 50 Art lenses. If there is light though the 16-35 sees the most time on my camera. Though w/ this much resolution, a 20 on the 5dR crops I would think very nicely to a 35 equivalent... hmmmm.

If I didn't already have the 24, this would be a definite acquisition. I don't do astro enough to buy up 3 stops for 20mm field of view over the 16-35 or loss of field from the 24. 

If I didn't have a great wide, ultra wide capability already, this would be so done.


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## TeT (Dec 29, 2015)

Talley said:


> TeT said:
> 
> 
> > Someone finally made a sharp 20mm 1.4 AF...
> ...



let me restate my question... why is the 24 ART not as sharp as the 20 ART & the 35 ART;


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## StudentOfLight (Dec 29, 2015)

I'm typically using my 24L II at f/2.5-2.8 or if I want sharpest details across the frame then f/5.6. At these settings the Canon lens quite hard to beat. The Sigma 24 Art was hardly an improvement over my trusted 24L II., and didn't justify me losing any CPS brownie points. 

The vignetting performance is is indeed impressive and clearly superior to the Canon 24L II. With the announcement of the 20-Art I again thought that it was gonna be time to sell off my 24L II but yet again the Sigma Art falls short of what I thought it would be.

As already mentioned of primary interest to me is the resolution at f/2.8. When pixel-peeping the corner performance is noticeably weaker than the Canon:
http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=1005&Camera=979&Sample=0&FLI=0&API=3&LensComp=480&CameraComp=979&SampleComp=0&FLIComp=0&APIComp=3

I believe these lenses deliver maximum resolution between f/4.0-f/5.6:
http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=1005&Camera=979&Sample=0&FLI=0&API=5&LensComp=480&CameraComp=979&SampleComp=0&FLIComp=0&APIComp=5
The Canon again delivers good corners although the Sigma looks a touch sharper in mid-frame. The Sigma however (even by f/5.6) still shows astigmatism in the corners, which I'll touch on again further below...

Another aspect of image quality is distortion. The Canon is again noticeably more rectilinear:
http://www.the-digital-picture.com/Reviews/Lens-Distortion.aspx?FLI=0&FLIComp=0&Lens=1005&Camera=453&LensComp=480

When applying distortion correct the corners will be stretched out, further exacerbating the astigmatism already present in the image. So if you want to go rectilinear the Canon will produce better corners and a more usable frame.

So while the 20-Art is an interesting lens, it does not offer enough for me to part with my reliably-focusing, built-like-a-tank, weather-sealed, CPS-qualifying 24L II. On the other hand, if I were in the market for a new super-wide f/1.4 then I'd be very happy with the range of choices on offer now.


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## Sabaki (Dec 29, 2015)

I would assume the 24mm TS-E outperforms both?


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## StudentOfLight (Dec 29, 2015)

Sabaki said:


> I would assume the 24mm TS-E outperforms both?


Yes, but f/1.4 autofocusing lenses do have their advantages for low-light events, and wide maximum apertures are prized for non-tracking astro shots.


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## Sabaki (Dec 29, 2015)

StudentOfLight said:


> Sabaki said:
> 
> 
> > I would assume the 24mm TS-E outperforms both?
> ...


Thanks S.O.L.

Me and my shorted sighted comments  :-[


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## JohnDizzo15 (Dec 29, 2015)

Loving the 20 Art so far. It is amazingly sharp in the center, has shockingly smooth bokeh when you can create some, good contrast, pretty good focusing speed (adapted), and distortion isn't anywhere near as bad as I was expecting it to be. All in all, for the discounted price I got it at, the best wide angle bargain I've had to date.


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