# PZ tests Sigma 20mm f/1.4 Art on both 5DSR and 5D2



## ahsanford (Mar 31, 2016)

Fascinating:
http://www.photozone.de/canon_eos_ff/973-sigma20f14art?start=1

PZ switched over to a 5DSR for its FF testing last year, but they haven't exactly set the world alight with a massive lens retest effort like DXO has. But in a new wrinkle, they slapped the same lens on their prior reference rig, the 5D2.

Does anyone have any thoughts on this.... or are you all still angry at the coma performance that crushed your astro hopes and dreams? 

- A


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## Random Orbits (Mar 31, 2016)

Interesting. I haven't used a camera with more MP than 22, so I can't comment on their reports of it being soft wide open at the periphery with the 5DS. AF with center points (on 5DIII) is good after AFMA, but both left and right sides with the cross points front focus (by roughly the same amount so it's not a decentering issue) when the subject is relatively close. It also seems to need higher contrast targets to be able to focus.

This is also my first Sigma lens. I got it when it went on sale earlier this month (and came with a free dock). I'm not a big fan of their finish/design concept. It looks good in product shots, but I like it less when I am handling it. The glossy bits seem like they will show marks/scratches much more than a matte finish. 

I expect the next great astro lens will be Canon's 24L f/1.4 III with the same BR technology that the 35L II sports. ;D


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## ahsanford (Mar 31, 2016)

Random Orbits said:


> Interesting. I haven't used a camera with more MP than 22, so I can't comment on their reports of it being soft wide open at the periphery with the 5DS. AF with center points (on 5DIII) is good after AFMA, but both left and right sides with the cross points front focus (by roughly the same amount so it's not a decentering issue) when the subject is relatively close. It also seems to need higher contrast targets to be able to focus.
> 
> This is also my first Sigma lens. I got it when it went on sale earlier this month (and came with a free dock). I'm not a big fan of their finish/design concept. It looks good in product shots, but I like it less when I am handling it. The glossy bits seem like they will show marks/scratches much more than a matte finish.
> 
> I expect the next great astro lens will be Canon's 24L f/1.4 III with the same BR technology that the 35L II sports. ;D



I rented a 35 Art and immediately hated the glossy bits. I missed my textured engineering plastic and metal from my L lenses. Hell, I preferred my nice 28mm f/2.8 IS USM's handling over it.

Nothing on a camera should be glossy/smooth (besides the glass, VF, and LCD) -- if there is any 'traveling music' between mount and front element that isn't taken up with distance scale, switches and focus/zoom rings, _it should facilitate grip_. You can't hold 'pretty', right?

- A


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## photon (Mar 31, 2016)

ahsanford said:


> You can't hold 'pretty', right?
> 
> - A



Oh yes you can. Oh yes


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## IglooEater (Mar 31, 2016)

ahsanford said:


> Does anyone have any thoughts on this.... or are you all still angry at the coma performance that crushed your astro hopes and dreams?
> 
> - A



Still angry. Not at poor coma performance, but that sigma advertised it as "designed to minimize coma aberration", when it wasn't. . Actually not angry, just a wee bit disappointed.


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## ahsanford (Mar 31, 2016)

IglooEater said:


> ahsanford said:
> 
> 
> > Does anyone have any thoughts on this.... or are you all still angry at the coma performance that crushed your astro hopes and dreams?
> ...



I'm stunned a company so technically accomplished (of late) had the gall to put an astro drool-worthy product out that lacks _the key thing that camp needs_. (I don't shoot astro, I am just parroting the general opinion when the reviews first came out: 'poor coma = why bother')

It's a fine lens and I'm sure there are a host of other uses -- events, concert photography (shooting up close behind stage, in the pit, etc.), and some ambitious environmental portraiture perhaps. This lens will have its devotees, don't get me wrong.

- A


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## Larsskv (Mar 31, 2016)

I have the Sigma 20 ART, and I am very satisfied with it on my 5Ds. My main purpose for buying it was for northern lights shooting, and it is absolutely fantastic for that purpose. It is very usable even at f/1.4.

Those criticizing it for bad coma, I must agree that it isn't perfect. However, I compared it to pictures I took with a Canon 24LII some time ago (not side by side), and found the Sigma to be much, much better than the Canon lens in that regard.

Focus accuracy is close to perfect, I think. After an in camera AFMA calibration I haven't had a miss with it´s focus that has ruined a shot. Focusing on eyes with off center single AF-points works very well. I guess that the wide angle and comparably wide depth of field contributes to good focusing results. I should mention that I haven't tried the AF-servo mode with it.

I find it to be a little bit sharper than my Canon 16-35 f/4L IS, even when stopped down to f/8, f/11 and f/13, but it requires pixel peeping to notice it. Contrast is very good.

It is too big and heavy to be a good walk around lens, I think, but if you need that wide aperture, I believe this lens is the way to go.


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