MTF Tests for the Sigma 14-24mm f2.8 Art Series Lens
Most of you know I’m a big fan of Sigma’s Art prime lenses. They give superior optics at excellent prices just about every damn time. I’ve been more mixed in my opinions of Sigma’s Art zoom lenses. I thought the Sigma 24-105mm f/4 Art was the best 24-105mm I’ve ever tested (and I hate testing 24-105s). The Sigma 24-70mm f/2.8 Art, on the other hand, I thought was adequate.
I wasn’t sure what to expect from the Sigma 14-24mm f/2.8 DG HSM Art, so I was eager to test it and grabbed copies as soon as we had them in stock. Why then, you may logically ask, am I just now writing it up? Well, partly because I have jobs that like, you know, pay me to do stuff. And somewhat because this became an exciting learning experience that I’ll tell you about at the end of the post.
About the Lens
Years ago, Nikon came out with their Nikon 14-24mm f2.8G ED lens. It was a revolution; wider and sharper than any other wide zoom made at the time. It remained the gold standard of wide zooms for years. Sigma isn’t filling a void here; Nikon already has an excellent 14-24mm, and Tamron has the not-quite-as-wide but really close 15-30mm f/2.8 Di VC USD.
The Sigma is less expensive than the Nikon by $400, but $200 more expensive than the Tamron 15-30mm f/2.8 Di VC USD. The Sigma, at 1150 grams is a bit heavier than the Nikon (1000g) and about the same as the Tamron (1100 gm).
So I thought that the new Sigma should be as good as the Nikon 14-24mm and better than the Tamron 15-30. That’s a tough task. Yes, I’m aware someone is going to make noise about other lenses. First, f/4 is not f/2.8. Second, 16mm is not 14mm, they are very different beasts (not to mention, most 16-35mm zooms are actually 17mm at the wide end).
One Disclaimer
Of course, the usual ‘this is not a lens review, it’s an optical test’ stuff applies to this post. One other thing needs to be mentioned when we test full-frame f/2.8 lenses wider than 16mm; we are either right at, or possibly past, the limits of our machine. It’s complex, it’s arguable, but it deserves mention that you should probably consider the graphs in this post ‘close, but might not be exact’ at the outer edges.
Also, I’ve violated my usual testing protocol for the first time, and I think you should know that. The test I’m showing you today is my second set of 10 copies of the lens, not the first 10. If you’re interested in why you can read about it in the addendum.
Optical Testing
As is our practice with 2x zooms, these lenses were tested at both ends (we do middle focal length testing on 3x and longer zooms). To start with, let’s mention the actual focal length of the lens is 14.3mm to 23mm. I mention this because that’s less ‘fudging’ than the label usually has; +/-5% is pretty standard for a zoom. Distortion is also reasonable: 0.8% at 14mm and 1.1% at 24mm. At both ends the distortion is mildly mustache shaped – a bit like the Zeiss 21mm f/2.8.
MTF of the Sigma 14-24mm f/2.8 DG HSM Art
At 14mm
This is an excellent resolution. About halfway to the edge, we start to see some astigmatism-like separation of the sagittal and tangential lines (it could also be the lateral chromatic aberration).
As I mentioned above, 14mm full-frame lenses are right at the limits of our machines automation. The drop in tangential MTF you probably note at 4mm away from the axis is perhaps a testing artifact; I won’t bore you with details about distortion being mapped at insufficient points for a very wide-angle lens. It could also be caused by an aspheric element. I can’t say for sure.
At 24mm
The resolution is even better at 24mm, just excellent across the field, and with no testing artifacts.
Stop-Down MTF
The above graphs are the average of all ten copies tested at the widest aperture. We took one typical copy and stopped it down for retesting. There is a marked increase in resolution at f/4 compared to f/2.8. There was very little change between f/4 and f5.6 so I’m not going to clog things up with those graphs.
14mm
24mm
You may notice that the MTF graph looks a little worse at the edges at f/4. This is a complicated thing that involves distortion, the lens’ field curvature, and a change in focus point of the machine, not a real thing.
MTF Comparisons
Nikon 14-24mm f/2.8G ED
We’ll start with the comparison to the long-term gold standard, the Nikon 14-24 f/2.8G ED. The Nikon is a much older design, of course, but still a superb lens.
At 14mm
Here is an excellent example of two great lenses that are different, not one-is-better. Both are excellent in the center. In the outer 1/3, the Nikon has less sagittal-tangential separation; the Sigma has higher resolution. Will that make a difference in your image? With careful comparison, you might notice the Sigma has better corner resolution, but perhaps busier bokeh. You might not notice any difference at all.
At 24mm
At 24mm the Sigma is strutting its stuff. It’s sharper everywhere. This difference should be noticeable, for sure.
Tamron 15-30mm f/2.8 Vi DC USD
At 14 vs. 15mm
The Tamron is an excellent lens at the wide end, very comparable to the Nikon. As with the Sigma-Nikon comparison, I won’t try to call better (especially given that we’re testing at the limits of our bench). The Sigma may be a bit better in the center; the Tamron maybe a bit better at the edges. Again, though, we’re straining the limits of our testing capabilities here, so I can’t say there’s any noticeable difference.
AT 24mm vs. 30mm
Again, it’s not close at the longer end; the Sigma is clearly better here.
If you want a really good example of just how hard it is to do 14mm, here’s a comparison of the Sigma 14-24mm f/2.8 with the Canon 14mm f/2.8 prime. Depending on what you emphasize, the Sigma comes close to violating Roger’s Prime Directive: No zoom is as good as a prime. In this case, the zoom may be better.
The Canon is not the best 14mm prime; I chose it because f/2.8 to f/2.8 makes a nice comparison. The Sigma 14mm f1.8 Art is the best 14mm prime. At f2.8 is better than any of the others. So Roger’s Prime Directive holds true.
Field Curvature
Let’s leave the fanboys behind to argue about the comparison MTFs and get into something useful for photographers who actually use the lens; the field curvature.
14mm
The sagittal field is a gentle M curve (lower left) while the tangential field (lower right) is a strong W. This gives the overall field (upper left) a bit of a U shape, and more importantly, means there’s going to be some astigmatism at the edges. It’s a 14mm lens, after all.
The strong field curvature affects the standard MTF curve (it is focused in the center, so the edge MTF is low partly because it’s out of focus). We can pull the data above to give Best Individual Point MTF (BIF). This is a theoretic measurement, showing how much resolution you can get if you focus on that specific point rather than the center.
Below is the center focus MTF on the left, the BIF MTF on the right. As you can see, if you focus off axis, you can get near-center sharpness just past halfway to the edge. Beyond that, you can get good sharpness, but you will have some astigmatism.
As I mentioned above, if you focus off axis, the center of the image will get softer, because of field curvature. Since 14mm is used for landscapes at times, it can be useful to find the best focus point – the place that if you focus there, you get the best overall sharpness from corner-to-corner. Below is a graph showing where we calculate that point should be, and what the MTF would look like if you focused there.
So, if you want to get the best edge-to-edge sharpness on your landscape shot, focus a bit less than halfway to the edge of the image; that will give you the best average sharpness across the frame.
24mm
At 24mm the tangential field is still slightly W shaped, while the sagittal is a shallow U shape. The important thing is they are more similar to each other, and the overall field is a gentle U with less astigmatism than at 14mm. This is a really nice performance for any lens (even a prime) at 24mm.
When we compare the center focus MTF (below left) with the Best Individually Focused MTF (below right) we see that at 24mm you can get excellent sharpness throughout most of the field; even at the edges, things are very good.
If we find the focusing point that gives our best overall focus, once again it’s at 8mm from the center, just about halfway to the edge of the image. That’s convenient; the Best Average Focus point is at the same place at either end of the zoom. Less to remember.
Conclusion
I said at the beginning that I expected this lens to be at least as good as the Nikon 14-24mm f/2.8 and better than the Tamron 15-30mm f/2.8. I think it’s pretty apparent that while they are all within hair splitting distance of each other at 14mm, the Sigma is the best at 24mm. Optically, this one is worth the money and the best overall 14-24mm zoom. There are lots of other things that go into choosing a lens, but at these very wide angles, things like autofocus speed are not big points.
That being said, if you’re buying a 14mm lens to be a 14mm prime (and some of you are), then all three of these do very well. Honestly, though, for a little more money you should consider the Sigma 14mm f/1.8 Art if that’s the case. If you’re thinking of matching a 14-24mm f/2.8 with a 24-70mm f/2.8 to collect the whole focal length set, then the Sigma is the best optical choice.
Two things I’ll mention. First, for the 72,534 of you that want to compare it to 16-35s, go right ahead. But it’s not a fair comparison, and I’m not going to do it. 14mm is very different than 16-35; much more difficult to design and manufacture. If a 16-35mm will meet your needs, and hold your filters without additional contraptions, then get a 16-35mm.
Roger Cicala and Aaron Closz
Lensrentals.com
July, 2018
Addendum: Sigma’s Response
Our protocol is always the same: the intake people inspect and test lenses on test charts, fail anything that’s obviously bad and pass the rest on for testing. I test the first ten lenses they send me to write the blog post.
This time a weird thing happened. On testing day 1, I tested the first eight copies of the Sigma. At 24mm five of them were identical and excellent. Three were not OK and was a big gap between the two groups. This is NOT normal. Generally, we see a cluster of lenses that are good, a lens that’s not quite that good, another not quite as good as that second lens, etc. In other words, the variance is always a steady trend away from best.
This is not something I’ve ever seen before in testing hundreds of lenses. I have a good working relationship with Sigma, so I emailed them as a courtesy, as I do with any manufacturer that corresponds with me. (They generally ask me to retest and want to argue about why my results aren’t valid. I generally retest and find my results are valid.)
Sigma didn’t do this. Instead, they asked for the serial numbers of the lenses. A few hours later they told me they had pulled the tests of those lenses at the end of the assembly, that the three lenses in question had tested much better than this at the factory, and asked me to send them to Japan for repeat testing.
Most of you don’t realize the enormous shock this caused me. I’ve been testing lenses for a decade and working with manufacturers for nearly that long. Leica has this kind of testing for every lens. Zeiss has it for certain lenses in their lineup. Nobody else does. Leica lenses. Some Zeiss lenses. Sigma Art lenses. Yes, I know all about other claims of ‘we test every lens’; that means it was mounted to a camera to program the AF firmware. Nobody else (with the possible exception of Canon with some of their newest lenses, and I’m not certain of that) is testing every copy optically and keeping the results on file.
Ten days later (shipping to Japan takes a while), Sigma emailed to tell me the lenses I sent back tested much worse than their original end-of assembly tests. Their new tests agreed with my findings and were, in their words ‘not acceptable for this lens.’ I’ve heard ‘this lens is within spec’ from manufacturers on lenses I knew were bad so often, for so long, that I reread the email just to be sure. To paraphrase a bit: “We have retested the lenses and agree with your findings. They aren’t good now. They were quite good when they left here. We’re investigating to find out what happened.”
Then they had their engineers disassemble the lenses and found some minor damage to rollers consistent with an impact that had caused the problem. I’ll be blunt, usually, I’d expect a ‘so you guys must have dropped them’ next, because these came from 3 different suppliers. And that is certainly possible. The lenses passed through several hands here on their way to me, and while very rare, things get dropped (and that people dropping don’t always admit they’ve dropped).
Instead, Sigma said they would track the shipment and see if the lenses were in the same crate or pallet during transit. Then they told me something that made me nearly weep with gratitude, showing that in a few companies engineering, not marketing, still runs the show:
Our engineers have also taken a number of new lenses from the assembly line, dropped them in various ways, and then disassembling them to look for damage. We did this until we had reproduced this type of damage. We will now see if there are changes we can make in the lenses or packaging to prevent this from happening in the future.
This is, in my opinion, what superb engineering and quality assurance are all about; look for any weaknesses and strengthen them. I’ve been working in this industry for many years, and this is the attitude I wish every company had, but few do.
Also, to be as certain as I can that the tests I’ve presented here are representative, I’ve tested a total of 25 copies now; the three damaged lenses were the only ones with any issues.
OFFTOPIC – And a bit of fun, for both of you that read this far.
I LOVE http://splasho.com/upgoer5/ where you have to write using only the 1,000 words most commonly used in American English. So, I rewrote a couple of paragraphs until they passed the test. If you want to try your hand at it, the two original paragraphs are under “14mm field curvature”. Post your results and shame me with how poorly I did.
The way the field moves changes how close to perfect the MTF (which is focused in the middle) is. We can pull the numbers above to give Best-at-each-point MTF. This is not a real world thing, because if you focus on that point, rather than the middle, the middle gets soft.
Here is the middle focus MTF on the left, and the Best-at-each-point MTF on the right. As you can see, if you focus away from the middle, you can get as good as you would see in the middle, until you go past half of the way to the edge. If you go further you can get good pictures, but the lines going away from the middle won’t be the same as the lines going across those lines going away from the middle.
55 Comments
Carleton Foxx ·
“Then they told me something that made me nearly weep with gratitude…” now you know how your readers feel every time you post one of these articles.
So, please keep taking your Lipitor and remember that you don’t have to eat the whole rack of ribs when you go out for barbecue.
William Dyer ·
Thank you for this extensive test report. I appreciate all the time and effort you put in, and your reviews do have an impact on the lenses I choose to purchase. While I think I’ll stick with my Tamron 15-30, having invested in a filter holder and 150mm filters, it is interesting to see it against the Nikon and Sigma. And as the owner of these Sigma lenses: 35 Art, 50 Art, 24-105 Art, 135 Art, 150 macro and the Sig-monster 300-800, it’s heartening to know Sigma’s engineers are serious about quality lenses. I remember many years ago, Sigma made a 24mm 2.8 with built in skylight, yellow, blue and orange filters. Very convenient, but the image quality was awful. Those days are gone.
Andre Yew ·
Thanks for the test and the cool Sigma story, but now I can sense the lens hypochondriacs lining up …
Speaking of which, what did the damaged lens results look like? Was it just lower overall resolution all around, or was there some kind of obvious asymmetry in the test results? I’m wondering if a normal person without an optical bench could have seen this with some kind of asymmetry test at home.
Roger Cicala ·
If you had two side-by-side you’d see it, there was an overall reduction in resolution and there was some side-to-side variation. If you compare this full graph to the average 24mm MTF above, you’ll see the difference easily.
The question is more why didn’t the screening techs see it. Their answer was they were all great at 14, and being the first batch the techs didn’t know what to expect. They were thinking ‘like the Tamron 15-30, which is great at 15 but weaker and with variation at 30mm. This was compounded because the lenses came in batches of 3 or 4 from different suppliers, so nobody on that first day got to look at all the lenses except me.
https://uploads.disquscdn.com/images/c920da658f721305d4ef6ae334d7c34a1ea22dd232d429b103907efd2f2c055b.png
Andre Yew ·
Thanks for sharing that graph Roger! That does look markedly different from the graphs above, but as your techs also thought, not completely out of line for a wide zoom.
Athanasius Kirchner ·
Oh, I can already see the forum headlines:
-DEFECTIVE SIGMA ART 14-24MM!?
-How many people have a broken Sigma 14-24mm? (Poll)
-I fear my new UWA zoom might be damaged – is yours too?
It’s too late now. The paranoia spreads like wildfire :/
Clayton Taylor ·
Roger, this might be your most significant blog post yet – not one but TWO bombshells! The fact that the Sigma zoom almost violated Roger’s Prime Directive is significant. The story in the Addendum about Sigma’s reactions to your tests left me amazed. My level of appreciation and respect for Sigma as a company has risen dramatically. I am totally in love with my new a7III, and now there might be an Art Lens in its future.
I am guessing that someone at Canon, when reading your post, uttered the Japanese equivalent of “Oh, crap!” – not once but twice.
Last thing – does this mean that, like a Marvel action movie, we now have to read right to the very end of all your future posts in order to find Cicala Easter Eggs?
CodeCurmudgeon ·
OMG – Now I know why I love Sigma Art lenses. I’m just hoping that the new E-mount lenses addresses the focus performance problem.
Athanasius Kirchner ·
That rewritten paragraph is terrible, but I highly doubt I could do better.
Please keep on using your technical language – if that doesn’t scare the artsy types away, the focus field graphs and conspicuous absence of cat photos will 😀
Tom Hoyle ·
I’ll probably never own this lens, but Roger your blog post is still well worth reading. Thanks for always being entertaining and informative.
Brandon Klemets ·
Worth noting the Tamron is the only option if you need pro weather sealing or image stabilization
Roger Cicala ·
Very true on the stabilization, Brandon. I won’t believe in weather sealing as long as the warranty doesn’t cover water damage, but I’ll go with ‘more resistant’ and that, too, is a pertinent point.
Ben ·
The cynic in me says their marketing department knows exactly how much of an influencer you are and told you exactly what was needed to ilicit r addendum. I have zero reason to believe this is true, but it’s worth asking if they sent you their tests results. I had the 35mm Art when I was Canon user and now use the 135mm 1.8 adapted on the GFX. Both are fantastic lenses, so I’m not surprised by their QA. They have always claimed to use their Foveon sensor to test every lens.
Roger Cicala ·
I can say I don’t know anyone in their marketing department (and all marketing departments despise me; of which I am most proud). I directly contacted and spoke with only engineers (we have had technical discussions about testing for years and I have met a number of them) and their response was immediate. The discussion was entirely about test results, testing, etc., I sent them all of my results and they sent me theirs.
David Bateman ·
Dropping lenses off the line to reproduce damage sounds like the best job ever.
Jeremy Van Pelt ·
Not sure about that. I would feel pain each time I did that to a beautiful lens, even though it was for a good cause.
Astro Landscapes ·
It’s a tough job, but somebody’s gotta do it. I’ve got an iron stomach, (I love driving on windey roads!) …so I’d be happy to drop a couple lenses in the name of R&D.
Partly because I’ve already dropped lenses enough myself to fully understand the frustration of gear this just isn’t designed right…
Arlington Brian ·
No reason to make people do that, they can just borrow a cat. They love knocking expensive stuff off of tables.
Franck Mée ·
Okay, here’s my take on the “only common words” challenge. I’d say, as a French, I thought it’d be easy for me (I don’t know that many words to start with), but it was actually rather difficult — what, “quality” isn’t even in your top 1000 words?!
The way the field is not straight changes the lines about how good the picture is (it is focused in the middle, so the how-good-lines are lower on the edge because it is out of focus). We can work the numbers above to give Best Number for Each Point. This is not a real thing, it just shows how good you can get if you focus on that point rather than the middle.
Here is the how-good-lines focused on the middle on the left, the Best Number for Each Point on the right. As you can see, if you focus off on the side, the area where you can get almost as good as in the middle is a bit wider than half the picture. Further, you can get a good picture, but lines will look different if they’re one way or another.
Roger Cicala ·
It’s a very deep thought, that quality is not among the 1,000 most common words.
I think your translation is much clearer than mine.
obican ·
Are you kidding, even the word “thousand” is not among the top 1000 words 😛
kimH ·
Excellent 🙂 – actually it struck me that I often focus landscapes about half-way to the corner(s) of the image. Now i know why 🙂 🙂
Samuel H ·
That Sigma story in the adendum is just mindblowing. It shouldn’t, but it is. I’m truly amazed.
Franz Graphstill ·
That’s wonderful news about Sigma’s idea of quality control.
I’ve been getting thoroughly sick of the claims from various people that Sigma Art lenses can’t focus reliably, and that Sigma has no idea of quality control. This is going to be my favourite counter-example from now on.
I’m not interested in wide-angle lenses – nothing wider than than 50mm, in fact. The Sigma Art 85mm and 135mm, though, are rapidly becoming my favourite lenses. Yeah, they are big, but I don’t care – I look at the image quality that I get, and laugh at the people who complain about the weight (well, they have to complain about something, and that’s about all they have!).
Messier77 ·
Roger, thanks for the wonderfully in-depth test/post. Any chance you could post the BIF MTF for the Sony 16-35GM? Thanks!
Dragon ·
One note re the Tamron. Your earlier testing of Tamron showed that it was very good at 24m (actually 23mm because your were comparing it to the Nikon at the time and didn’t want to push the Nikon the stop). At 23mm it is not quite as sharp as the Sigma in the center, but probably the best of all across the field. I have one and have found it to extremely sharp at 24mm on a 5DSR. The only downside I know of is that it came out before the Tap-in console and you have to send it in for firmware updates. My favorite Sigma is the 150mm macro. It eats razors for breakfast.
Max Manzan ·
Thank you Roger for this blog post, I found the addendum very interesting.
I’ve been admiring Sigma as a company since they introduced their Global Vision concept and particularly their Art lens line. Now I’m admiring them even more.
obican ·
Thank you, Roger.
kimH ·
Again an excellent story for all us out there “geeking”. Adding the SIGMA story is the coolest, you have officially become an authority @LR – but WE who follow you with joy, all knew that already. Thanks for the work, please don’t stop!
ipdouglas ·
Very interesting real-world article! Totally agree with the Quality Assurance activities. Might have expected the Sigma engineers to have conducted ‘drop tests’ first rather than later but perhaps the damage was from some unusual impact different from a norm? Looks like a new QA test here?
The comments and results do not exactly correlate with the group wide-angle zoom test where the Nikon 14-24mm was preferred rather than equivalent? However as usual I absolutely love you tests and the blog so thanks Roger!
Bakari Taylor ·
That was really cool to hear about Sigma’s response. Before the Art series of lenses no one was really taking Sigma seriously, they were a great inexpensive, so so option. Today they are are one of the best lens manufactures period. It really is quite amazing.
Astro Landscapes ·
1.) Could it be possible that these field curvature measurements are /significantly/ different at infinity, where field curvature matters a whole lot for nightscape photographers?
2.) It is pretty clear that the Sigma 14 1.8 Art is just bonkers, compared to any of the zooms that get to 14/15mm. However, do you have any results for the new Rokinon 14 2.4 SP / Samyang 14 2.4 XP, …or have you completely given up on having these brands in your arsenal at LR? [EDIT: scratch that. I do see that the 14 2.4 is in your arsenal. Have I missed its review being posted on this blog, or has it just not been put on OLAF?]
3.) “Our engineers have also taken a number of new lenses from the assembly line, dropped them in various ways, and then disassembling them to look for damage. We did this until we had reproduced this type of damage. We will now see if there are changes we can make in the lenses or packaging to prevent this from happening in the future.”
…MY DREAM JOB EXISTS. (I need to learn Japanese and get a few engineering degrees, though…)
Roger Cicala ·
These are done at infinity
Astro Landscapes ·
(Insert heart-eyed emoji here)
bdbender4 ·
Holy cow! Three cheers for Sigma! Integrity is loose in the world, in a week when integrity in the political world… let’s not go there.
Here is my wish: that for their next act, Sigma will design some really good SMALLER primes. Another approach besides the huge-heavy-distagon-packed-with-glass.
And Roger, really, you love the splasho thingy? What is writing without wit, without soul, without eloquence, vivacity, sophistication, clarity, fine degrees of articulateness? Where else can you use 25 cent words? Tsk, tsk.
Astro Landscapes ·
On another note, I must say I’m still hesitant about Sigma Art’s long-term durability, compared to Canon L and Nikon flagship glass, let alone Zeiss. I’m a wedding photographer for my day job, (pun intended?) and I’ve been co-workers with a pretty huge team of photographers that has had nothing but grief from their Sigma Art glass, from AF woes to serious durability / longevity issues. I’ve seen multiple copies of the 24, 35, and 50 Arts that have literally rattled to pieces, coming apart at the mount or somewhere around the focus ring part of the barrel, …and the 24 Art is just horribly prone to getting terrible edges, even if all seems kosher mechanically.
For this reason, I’ve continued being only partly a fan of Sigma Art, and still partly a fan of Rokinon when necessary. (Such as at 24mm) However, since Roki-Bow-Yang’s lens “repair” department is almost nonexistent, …this news of actual factory spec testing has me very very pleased. I doubt they’re as discerning and thorough as a complete OLAF test, but at least it’s a start.
Probably what I’ll end up doing is buying a ~14mm lens directly from LR, either used or through the “I’ve rented but decided I want to own” program. (I forget the real name)
Marco ·
There are a lot of guys testing lenses and equipment out there but there is nobody like Roger
Ilya Zakharevich ·
Look whether the picture goes along a straight line, or goes away from the (straight!) part which reads and stores the picture. The worse this is, the worse is the “how-clear-at-each-point” drawing (this drawing shows how clear is the picture at different points). Really, in this case, if you want to make your picture clear in the middle, it stops to be clear at the edge.
On the other hand, we can work over the numbers above, and give you the drawing we name “most-clear-at-each-point”. This may be not very important to you; this drawing shows how clear your picture may be at every point if you do not care what happens at other points.
And now you can look at once at the “how-clear-at-each-point” drawing on the left, and at the “most-clear-at-each-point” drawing on the right. As you can see, to get your picture as clear as it is possible in the middle, you can move your most-important-to-be-clear point as far as half way to the edge. If you move it more, then it would be way easier to see that the lines going away from the middle are much more clear than the lines going across.
Roger Cicala ·
Love it.
Adam Palmer ·
More love for Sigma. I was sold after I got the 50mm 1.4 way back when. I know have sigmas from 20mm to 400mm. They sure know how to make a great lens at a reasonable price.
Maxim Podtopelny ·
I found myself crying at the end of addendum. I read this blog for many years and this was definitely the cutest thing I’ve ever read!
bdbender4 ·
When is a line not a line? When it is not straight. When is a not straight line not a not straight line? When it is a whole family of not straight lines. (When a whole family of not straight lines are happy in the middle, they are not so happy at the side.) If you want a happy family of not straight lines, you can say they are happy at another place you pull out of your ear. You can look and see how happy the family of not straight lines are at the out of your ear place. But don’t believe it. It is not real.
Down on the left is the very happiest family of not straight lines from the middle. The families of happy not straight lines from the out of your ear place are on the right. As you can see, if you play around enough you can make families of very happiest not straight lines away from the middle just past half way to the side. If you go further toward the side, the families of not straight lines get sad. Not so happy.
(So the deal is: you can have a few not straight lines in the middle that are really, really happy. But then the other not straight lines are
kind of sad. Or, you can make a lot of the other not straight lines kind of happy. Not really happy, but kind of happy. But then the not straight lines in the middle get sadder.
Or: “You can make some of the not straight lines happy some of the time, but you can not make all of the not straight lines happy all of the time.”)
Roger Cicala ·
Thr “Or” is perfect. I’m stealing that.
Ruy Penalva ·
This smells a little bit fantasy from Sigma. What king of shock could made this in this lens? Fabrication defect.
Roger Cicala ·
Ruy, not sure why you think that. We find drops are the most common cause of all lenses in our fleet becoming optically impaired.
Ruy Penalva ·
But that lens come from local distributor, what kind of shock could they have ben taken? I did not doubt that drops could impair a huge amount of lens. But seems to me a little fantasy to presume a shock in the original package. Do they have the same percentage of impairment? In other words, the three lenses behave uniformly under the curve? Sorry to not see in details your graphics that are becoming every day more hard to swallow and digest. My bet is this is not a kind of marketing from Sigma and Lens Rental?
Roger Cicala ·
As I mentioned, it is possible they were dropped here. Also ‘local distributor’ for us generally means from New York or California, so a couple of warehouses, several trucks, and a journey of a 1,000 miles or more.
Matt Krull ·
I really enjoy my little Sigma 60mm F2.8, and I’ve been saying for awhile that if Sigma releases a m43 60mm F1.4 I’ll pre-order it. Engineering and support like this are exactly what I want to support. Dear sigma: release an m43 foveon body and I’ll pre-order that too.
I’m happy to support companies like this with my wallet.
Roger, thank you for sharing the story.
Matt K ·
I really enjoy my little Sigma 60mm F2.8, and I've been saying for awhile that if Sigma releases a m43 60mm F1.4 I'll pre-order it. Engineering and support like this are exactly what I want to support. Dear sigma: release an m43 foveon body and I'll pre-order that too.
I'm happy to support companies like this with my wallet.
Roger, thank you for sharing the story.
Micah ·
At two years old, my Sigma 20mm ƒ/1.8 had the iris implode, locking the aperture lever, and breaking the aperture arm in my D2x. Sigma fixed the iris. It broke again. They fixed it again. It came back to me much softer–something was out of alignment. They said to send it back with some pictures showing the problem. I sent it back with some big prints of shots before and after. They recombobled it and brought it back to its former glory. No charge other than the first time shipping it to them.
That was ten years ago. Still works great!
I only wish Nikon USA service was so good!
suk it! ·
lets hope sigma can get any issues with their af under control. so there is no doubt. I know the vast majority dont have issues with them. but many oem fanboys go online like to bh/adorama and write negative reviews when they arent verified buyers has been inflated. on the internet anyone can be anyone and can say what they want and no one can verify it.
MusicIsMath ·
WOW I am in awe at the lengths you guys go to test your stuff, commenting just now on a previous lens test I mused about the field curvature actually being the thing that shows up in the resolution tests and here you are already measuring that and giving recommendations on it. You have made me into a fan, these are the best tests I’ve seen so far. Maybe if you had them in an easy to access database, it would make provide even more utility.
Michael Steinbach ·
Being an old guy with a long memory I remember the 80’s and even as late as the early 2000’s where Sigma was not a great lens name. I had a 24 mm that the aperture stuck wide open, and a 35-70 that’s zoom locked up. The later I sent in and NEVER saw it again. Customer service was non existent. Times and stiff competition have brought us all better lenses, what great time for photography. Thanks Roger for the excellent non-reviews!
Jim Barnwell ·
Thanks for the insight and confirmation I made a good decision. But otherwise…waaaay too much analysis for me. The lens is a great performer and equal to the Nikon. I’ve used both. Yep, this one’s heavier. Bottom line: Fair price, excellence performance, and, most of all, the customers like the results!
Moyang ·
Thank you for this wonderful test report. I wonder if you plan to test the new Sigma 14-24mm f/2.8 DG DN Art lens, which uses much newer optical formula and is optimized for mirrorless. Looking forward to know 14-24mm DN vs. 14mm f/1.8!