p.12 #1 · In Stock: Sigma 85mm f/1.4 DG DN Art ($1,199)
NJPhotographer wrote:
It's hard to tell because the angle of the head is different, and the hair is closer in on the face in the Sigma image, casting a shadow on part of the face, and making the face seem narrower.
But if pincushion distortion is too high, won't the standard lens profile fix it?
Yes, maybe the slightly different pose and framing makes a difference as well, but I have seen really wild distortion with this lens, which is not usual in an 85.
The problem with correction profiles is that for flat surfaces, or when everything is at the same distance, they are more or less fine (despite slight loss in resolution), but for real world, some undesirable results might happen when you apply a 2D correction in a 3D world...
We are focusing too much in sharpness at 300% and forgetting about more important things like rendering (not easy to test, but most don't even try, or do it incorrectly), color (the easiest to fix in the same camera and different lenses, not that easy between different camera brands...), or this distortion issue...
No doubt this new sigma will be a great lens when it comes to sharpness, but also remember that the GM is designed under corrected for spherical aberration to improve bokeh and general rendering...
p.12 #3 · In Stock: Sigma 85mm f/1.4 DG DN Art ($1,199)
mike_the_kraken wrote:
Can you link to some real-world samples of the distortion you’re seeing? I’m curious to how significant this is.
I don’t have real world samples, I hope the honest reviewers (Not the YouTube commercials) focus a bit more on that. Look at the review from Christopher Frost, I think this is the highest level of distortion in an 85mm ever.
p.12 #4 · In Stock: Sigma 85mm f/1.4 DG DN Art ($1,199)
numbertwo wrote:
The problem with correction profiles is that for flat surfaces, or when everything is at the same distance, they are more or less fine (despite slight loss in resolution), but for real world, some undesirable results might happen when you apply a 2D correction in a 3D world...
Generally speaking, I don't think this should be a concern. From what I understand about optics & physics (which admitted is not a whole lot), a lens could not distort (in the typical pincushion/barrel type of distortion that we're discussing) in a three-dimensional manner, this would require the lens to be capable of breaking basics laws of physics, for instance, seeing behind an object and thus distorting it/bring it into or out of view in a three-dimensional way.
Everything I know about this type of distortion tells me that two-dimensional corrections are completely appropriate, and many modern lenses are designed to have these qualities corrected in software rather than with glass. The drawback to correcting this type of distortion in software tends to be a loss of resolution and/or slight crop to the image.
p.12 #5 · In Stock: Sigma 85mm f/1.4 DG DN Art ($1,199)
numbertwo wrote:
I don’t have real world samples, I hope the honest reviewers (Not the YouTube commercials) focus a bit more on that. Look at the review from Christopher Frost, I think this is the highest level of distortion in an 85mm ever.
Given the way geometric distortion in lenses works, provided the distortion is simple and not complex, correction works fine regardless of the 3d a nature of the subject, since what is distorted is the 2d representation. This distortion is strong but it's pure pincushion, not wavey, so simple correction will work.
Of course correction reduces resolution a little, especially in the outer field. But this lens is about 10% higher in MTF even that the astonishingly high MTF DLSR version. So, and this is just an informed guess, the post-correction resolution ought to be as good or better as that lens.
So what we will end up with, post correction, is resolution as good or better than the amazing early one, and half the mass and volume! That is seriously impressive.
If there's anything that I"m not sure about yet, it's the level of mechanical (optical) vignetting. Mere shading is not a worry - the DR of our sensors is such that i'm fine with correction, or partly correcting it. But if there is too severe cats eyes caused by optical vignetting, it could create some slight oddities in the bokeh in the corners, where the corners are less OOF than the centre.
So I'm keeping an eye on the extent of that; but if that's not a major issue, this one is definitely for me. (I suspect the GM will still have bokeh that many will prefer, maybe even me, but the size and mass of this is a winner for me, and I suspect the contrast will be higher at wider apertures too, which for some images I'll prefer)
p.12 #6 · In Stock: Sigma 85mm f/1.4 DG DN Art ($1,199)
numbertwo wrote:
Yes, maybe the slightly different pose and framing makes a difference as well, but I have seen really wild distortion with this lens, which is not usual in an 85.
The problem with correction profiles is that for flat surfaces, or when everything is at the same distance, they are more or less fine (despite slight loss in resolution), but for real world, some undesirable results might happen when you apply a 2D correction in a 3D world...
We are focusing too much in sharpness at 300% and forgetting about more important things like rendering (not easy to test, but most don't even try, or do it incorrectly), color (the easiest to fix in the same camera and different lenses, not that easy between different camera brands...), or this distortion issue...
No doubt this new sigma will be a great lens when it comes to sharpness, but also remember that the GM is designed under corrected for spherical aberration to improve bokeh and general rendering... ...Show more →
in my opinion, I actually like the new Sigma a lot better for color than the GM. but I agree, there's not enough real world rendering comparisons happening, especially at mid and full body length portrait distances.
p.12 #8 · In Stock: Sigma 85mm f/1.4 DG DN Art ($1,199)
A new comparison, in french :
Pretty basic stuff, but one interesting thing : At 7 : 23, a bokeh comparison. Samyang on the upper left, GM on upper right, Sigma on bottom left. The Sigma is free of Loca but a little bit harsher.
One interesting thing : the Samyang doesn't show rounded bokeh balls wide open. Probably a little bit closed down compared to the "real" wide open ?
No real torture test unfortunately (complicated background at mid distance, etc).
p.12 #9 · In Stock: Sigma 85mm f/1.4 DG DN Art ($1,199)
Ayoul wrote:
A new comparison, in french :
Pretty basic stuff, but one interesting thing : At 7 : 23, a bokeh comparison. Samyang on the upper left, GM on upper right, Sigma on bottom left. The Sigma is free of Loca but a little bit harsher.
One interesting thing : the Samyang doesn't show rounded bokeh balls wide open. Probably a little bit closed down compared to the "real" wide open ?
No real torture test unfortunatly (complicated background at mid distance, etc).
Nice comparison.
Note: The images actually change place during the review, the key is that Sigma has a green dot, Sony a red one and magenta is Samyang.
p.12 #11 · In Stock: Sigma 85mm f/1.4 DG DN Art ($1,199)
jacquesvroom wrote:
Note to GabrielPhoto from Teo Rey:
"I think I speak for most of us when I say we would looove to see you do an in depth comparison between the two Sigmas, the Samyang, and the GM "
Including also any "portrait" lenses you might have in the 104-106mm range...
Indeed I will be doing that. I have specific models that can become pretty much human statues, so those are my go-to models for this kind of test. Believe it or not, some are just unable to hold a pose for too long I find it crucial to have as similar a pose as possible so people do not misinterpret a different angle for lens causing some facial distortions.
p.12 #12 · In Stock: Sigma 85mm f/1.4 DG DN Art ($1,199)
Interesting lens. I’m am basically very satisfied and happy with my Samyang AF 85 1.4
I love it’s rendering. Still I would love to give the Sigma a try someday. If there’s already a real world comparison between the Samyang 85 1.4 (which is even lighter) against the new Sigma, please let me/us know
p.12 #13 · In Stock: Sigma 85mm f/1.4 DG DN Art ($1,199)
From: GabrielPhoto
"Indeed I will be doing that. I have specific models that can become pretty much human statues, so those are my go-to models for this kind of test. Believe it or not, some are just unable to hold a pose for too long I find it crucial to have as similar a pose as possible so people do not misinterpret a different angle for lens causing some facial distortions."
I remember, in the early 1970's, looking at a bracket of 8x10 transparencies for a Christmas catalog theme-page ("Horchow", for you old-timers–when Roger Horchow was still the president). The set-up included a sweet bunny rabbit prominently among its props. Even though the 3-shot bracket exposures were obviously taken at least several seconds apart, the rabbit looked absolutely identical in each.
Turned out the photo guys had bought a bunny at the pet shop and frozen it!! Luis, I hope you are not secretly working in that older tradition!!
p.12 #15 · In Stock: Sigma 85mm f/1.4 DG DN Art ($1,199)
Vignette amount does not bother me much. I’m more concerned about distortion which is pin cushion. Typical of the longer focal lengths. So not a copy lens.
This can be problematic with close ups of people. But a good lens profile will fix it. Kind of normal to a certain degree. Bokeh looks fairly nice, maybe not GM but certainly this looks to be far better AF speed which was a big issue for me on the GM. Forced me into Batis and Sony 1.8 which did a nice job focusing but more a clinical look. Hard to tell if this matches the GM with look and rendering but looks damn close. I have the Sigma 24-70 than the Sony 135 so I am missing a 85. This maybe it. BTW on the Samsung which has a nice look but I simply can’t trust the AF. So I swore Samyangs off.
As someone that’s a working Pro and a very good lens tester. I’m just not going to risk things to save a few bucks on Samyang. That’s me though
Back to the Sigma 85 I would really like to at least test this. Having had all the 85 lenses this one actually looks the best.
p.12 #18 · In Stock: Sigma 85mm f/1.4 DG DN Art ($1,199)
..........I'm on the fence with this lens but I sure am excited for Sigma to do the it's magic on the 35 1.2, 35 1.4 and 50 1.4..........maybe a 50 1.2 that is half the weight of the Canon RF?
p.12 #19 · In Stock: Sigma 85mm f/1.4 DG DN Art ($1,199)
The new sigma redesigned train is about to take off I think their 70-200 2.8 is next but wow that comparison of the GM and sigma 85 is really nice. This looks to be possibly the best 85mm we may have for sony now.
p.12 #20 · In Stock: Sigma 85mm f/1.4 DG DN Art ($1,199)
sismailian wrote:
The new sigma redesigned train is about to take off I think their 70-200 2.8 is next but wow that comparison of the GM and sigma 85 is really nice. This looks to be possibly the best 85mm we may have for sony now.
It's possible their new 70-200 will outperform the GM...a lens that never impressed me.
I like what I've seen sofar. If b&h has one of those deal zones again for this lens it would be sweet 
