# Review: Canon EOS 17-40 f/4L by DxO Mark



## Guest (Jan 23, 2014)

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<p>DxO labs has tested and reviewed the Canon EOS 17-40 f/4L.</p>
<p>From their review:

“Due to its more glamorous sibling this modest lens is often overlooked though it’s well known for its high-performance by Canon users. As a small, light, highly portable zoom it would make a great choice for travel, landscapes and general-purpose photography.”</p>
<p>Our own review by Justin echo’d this feeling. Justin has owned and used this lens from his very first day shooting, and it’s a completely viable alternative to the Canon 16-35 f/2.8 L if you can spare the extra stops of light. You can read our <a href="http://www.canonrumors.com/reviews/review-canon-ef-17-40mm-f4l/">review here</a>, and check out DxO’s <a href="http://www.dxomark.com/Reviews/Canon-EF-17-40mm-f-4L-USM-lens-review-Popular-high-performance-option">full review here</a> their lens comparison tool is an excellent resource if you’re into sharpness charts.</p>
<p>Source [<a href="http://www.dxomark.com/Reviews/Canon-EF-17-40mm-f-4L-USM-lens-review-Popular-high-performance-option">DxO</a>]</p>
<p><strong><span style="color: #ff0000;">c</span>r</strong></p>
<p><a href="http://www.bhphotovideo.com/c/product/279582-USA/Canon_8806A002_EF_17_40mm_f_4L_USM.html/bi/2466/kbid/3296/kwid/justin">Canon 17-40 f/4L at B&H</a>  | <a href="http://www.adorama.com/CA1740U.html?kbid=64393">Canon 17-40 f/4L at Adorama</a></p>
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## neuroanatomist (Jan 23, 2014)

Guest said:


> ... their lens comparison tool is an excellent resource



...if you only shoot in lighting equivalent to a dimly lit warehouse. :

Their _Measurements_ are useful, their Scores and the rankings which are based on them are generally meaningless (except in warehouses  ). 

I should qualify that be saying their Measurements _can be_ useful, when they're correct. They weren't for the 70-200 II, but they defended them until they silently updated them. Their measurements of the 17-40L are also suspect, as they apparently show it's as sharp in the corners as the center wide open, and sharper at f/4 than the 16-35/2.8L II stopped down to f/8 - I don't buy either of those.


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## mackguyver (Jan 23, 2014)

neuroanatomist said:


> Their measurements of the 17-40L are also suspect, as they apparently show it's as sharp in the corners as the center wide open, and sharper at f/4 than the 16-35/2.8L II stopped down to f/8 - I don't buy either of those.


There is a popular "explanation" for their results...Canon provided them with a hand-picked copy


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## roxics (Jan 23, 2014)

But how does this lens compare to the Sigma 18-35 f1.8? I know the L is full frame and the Sigma is not. But if both used on a Super35mm sensor, how do they compare?


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## arbitrage (Jan 23, 2014)

roxics said:


> But how does this lens compare to the Sigma 18-35 f1.8? I know the L is full frame and the Sigma is not. But if both used on a Super35mm sensor, how do they compare?



I think if I was shooting a crop sensor and wanted the very best, the Sigma would be the way to go from all the testing I've seen.


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## tron (Jan 23, 2014)

DXO is such a reliable site... ;D

http://www.dxomark.com/Lenses/Compare/Side-by-side/Carl-Zeiss-Distagon-2.8-21mm-ZF2-Nikon-on-Nikon-D3X-versus-Carl-Zeiss-Distagon-T-21mm-f-2.8-ZE-Canon-on-Canon-EOS-5D-Mark-II___334_485_326_483


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## Ricku (Jan 23, 2014)

I LOVE the range of this lens, but I hate the performance.

Give me a version II with tack sharp corners.

I'd much rather have a razor sharp 17-40 II than a razor sharp 14-24L.


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## Marsu42 (Jan 23, 2014)

Yippee, another 17-40L vs 16-35L thread 



neuroanatomist said:


> Their measurements of the 17-40L are also suspect, as they apparently show it's as sharp in the corners as the center wide open, and sharper at f/4 than the 16-35/2.8L II stopped down to f/8 - I don't buy either of those.



If they said that (I'm too lazy too look) the former is clearly bogus if they're referring to the very far corners - if you want that, don't get the lens or at least be prepared to stop down a lot. For the second piece, maybe they've got a very good 17-40L copy and a very bad 16-35L one...

... still, after getting the ff I can say that the lens is indeed excellent unless you're looking for corner sharpness wide open, f2.8 speed (imho seldom necessary at this focal length, and these are not very bokeh'ish anyway) - and it's light weight and moderate size is a great combination with the 6d.


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## sagittariansrock (Jan 23, 2014)

Ricku said:


> I LOVE the range of this lens, but I hate the performance.
> 
> Give me a version II with tack sharp corners.
> 
> I'd much rather have a razor sharp 17-40 II than a razor sharp 14-24L.



+1. Even better, a 17-40 f/4 IS. Pretty please...


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## tron (Jan 23, 2014)

Marsu42 said:


> Yippee, another 17-40L vs 16-35L thread
> 
> 
> 
> ...


 Size and weight is a serious advantage with f/4 zooms when one wants to travel lightly. I remember putting my 5D2 with 24-105 f/4L and 70-200 f/4L IS in a small Urban Disguise 30 ThinkTank bag and traveling light and decently equipped at the same time


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## tianxiaozhang (Jan 23, 2014)

I think it's fantastic.. (I wouldn't mind the 1635II either of course.. )


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## tron (Jan 23, 2014)

tianxiaozhang said:


> I think it's fantastic.. (I wouldn't mind the 1635II either of course.. )


You must mean the girls not the lens... ;D

As far as night sky is concerned a 2.8 would be a plus. However, all Canon wide angle zooms (and primes for that matter) suffer from coma (Only the new 24-70 2.8 II is reported to be greatly improved in that matter).


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## JonAustin (Jan 23, 2014)

The 17-40 was my first L lens -- purchased way back in July 2003 -- to replace the 24-85 I bought with my first SLR, the 10D.

It was mounted to my camera body 90% of the time when I was shooting with crop bodies (10D, 20D), where it's excellent, since the corners are cropped out, and it served as a standard-range zoom (27-64mm equivalent).

It doesn't get as much use since I moved to full frame; mostly for wide angle landscapes when I'm hiking (two FF bodies; one with 17-40, another with 70-200). But I doubt that I'll ever part with it, even if a version II is released. (If the version II has IS, I would be sorely tempted, though ...)


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## neuroanatomist (Jan 23, 2014)

mackguyver said:


> There is a popular "explanation" for their results...Canon provided them with a hand-picked copy


Canon would have had to custom-build one with a different optical formula...I seriously doubt that Canon could find a copy where the 17-40 at f/4 delivers corner sharpness comprarable to the center, and is better overall at f/4 than the 16-35 II at f/8.







Note that when looking at the 16-35 II, it's actually sharper at f/2.8 than at f/8 - also pretty unlikely. DxO's measurements of 17-40 show that it doesn't get sharper when stopping down to f/8, because apparently it's already very sharp wide open. Yeah, right... 




tron said:


> DXO is such a reliable site... ;D


Like I said, their Scores make sense if you always shoot in dimly lit warehouses. In 150 lux illumination, the better high ISO performance and dynamic range (you're going to boost those shadows, right?) of the D3x make the Zeiss 21/2.8 a better lens, and that clearly accounts for it's higher score. 

Oh, wait…you thought that the Scores were logically derived from the Measurements? Silly, silly tron. 




Marsu42 said:


> ... still, after getting the ff I can say that the lens is indeed excellent unless you're looking for corner sharpness wide open, f2.8 speed (imho seldom necessary at this focal length, and these are not very bokeh'ish anyway)


The 16-35L II doesn't deliver corner sharpness wide open, either. If you want that, you need to get the TS-E 17L or TS-E 24L II (and don't tilt/shift them too much).

Personally, I have found that the extra stop of the f/2.8 lens helps for low light shooting (and with 'normal' subject distances, you don't run into issues with too shallow a DoF). But I really think that extra stop of light is the only reason to pick the 16-35 II over the 17-40 - for real-world use especially stopped down a bit, there's not a significant difference between the two (or if you believe DxO, the 17-40 is actually much better : ).


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## Radiating (Jan 23, 2014)

roxics said:


> But how does this lens compare to the Sigma 18-35 f1.8? I know the L is full frame and the Sigma is not. But if both used on a Super35mm sensor, how do they compare?



This is something newbies often mix up. L lenses do not mean they have good image quality, just that they use expensive rare glass. L lenses in certain cases have delivered performance much worse than consumer level alternatives.

It's also worth mentioning that lenses designed for crop cameras use tighter tolerances in manufacturing which results in higher image quality (the parts are smaller so this is easier) so generally a lens designed for crop will perform better than a lens designed for full frame. The 17-40mm L is designed for full frame and performs nearly identically to the 18-55mm kit lens, but is more expensive and worse in nearly every way (though it's color and contrast is said to be slightly better, I don't really care personally).

The 17-55mm f/2.8 IS EF-S lens is better than either the 17-40mm L or the 18-55mm kit lens. The Sigma 18-35mm is the best crop lens available right now.

17-40mm 4.0 L vs 18-35mm 1.8 ART

http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=100&Camera=736&Sample=0&FLI=2&API=0&LensComp=854&CameraComp=736&SampleComp=0&FLIComp=2&APIComp=3


17-55mm 2.8 vs 18-35mm 1.8 ART

http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=398&Camera=736&Sample=0&FLI=1&API=0&LensComp=854&CameraComp=736&SampleComp=0&FLIComp=1&APIComp=2 

The 17-40mm L, 18-55mm EF-S IS II, and 17-55mm f/2.8 IS are not even worth comparing to the Sigma 18-35mm ART, the difference is incredible in favor of the Sigma.


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## neuroanatomist (Jan 23, 2014)

Radiating said:


> The 17-40mm L, 18-55mm EF-S IS II, and 17-55mm f/2.8 IS are not even worth comparing to the Sigma 18-35mm ART, the difference is incredible.


Yes, when you're comparing them on the same APS-C camera. But when you compare the EF lens on FF to the Sigma 18-35 on APS-C, it's a different story…

http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=100&Camera=453&Sample=0&FLI=1&API=2&LensComp=854&CameraComp=736&SampleComp=0&FLIComp=1&APIComp=3


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## Radiating (Jan 23, 2014)

Guest said:


> <div name=\"googleone_share_1\" style=\"position:relative;z-index:5;float: right; /*margin: 70px 0 0 0;*/ top:70px; right:120px; width:0;\"><glusone size=\"tall\" count=\"1\" href=\"\"></glusone></div><div style=\"float: right; margin:0 0 70px 70px;\"><a href=\"https://twitter.com/share\" class=\"twitter-share-button\" data-count=\"vertical\" data-url=\"\">Tweet</a></div>
> <p>DxO labs has tested and reviewed the Canon EOS 17-40 f/4L.</p>
> <p>From their review:
> 
> ...



I have a theory that DXO has been getting specially selected copies with perfect tolerances from Canon. Several of their tests are way better than average. Certainly not impossible, but definitely not "average" from what I've seen.


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## neuroanatomist (Jan 23, 2014)

Radiating said:


> I have a theory that DXO has been getting specially selected copies with perfect tolerances from Canon. Several of their tests are way better than average. Certainly not impossible, but definitely not "average" from what I've seen.



No doubt that explains why their initial testing of the 70-200/2.8L IS II showed that it was not quite as good as the 70-200/2.8L IS that it replaced… :

http://www.dxomark.com/Reviews/Canon-EF-70-200mm-f-2.8L-IS-II-USM-measurements-and-review

Can you point to some examples (other than the 17-40L, which as I stated, I think DxO's measurements are way too good to be even a cherry-picked copy)?


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## dude (Jan 23, 2014)

I love this lens. It is worth mentioning that at one time it was the cheapest L lens you could purchase. 

This lens is my go to landscape and daytime long exposure lens. Lightweight and wide. Yes, the corners are not great but it is an essential lens for my bag.


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## mrsfotografie (Jan 23, 2014)

neuroanatomist said:


> Guest said:
> 
> 
> > ... their lens comparison tool is an excellent resource
> ...



Well, they _did_ figure out that it's a great travel lens (at least they got that right), something that is also clearly stated on the Canon Europe website (and I agree!!) Doh!:

http://www.canon-europe.com/For_Home/Product_Finder/Cameras/EF_Lenses/Zoom/index.aspx


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## Cali Capture (Jan 23, 2014)

I have found this to be a great lens. Opted for this over the 16-32 becuase of price and I use a 24mm 1.4L for low light wide. I'm not a pro landscape photog so this serves my needs wide until something better comes out. I think we all agree Canon could use some help in the superwide range and Ziess's 15mm kind of said the same thing, sans auto focus and afordability!


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## sdsr (Jan 23, 2014)

Radiating said:


> It's also worth mentioning that lenses designed for crop cameras use tighter tolerances in manufacturing which results in higher image quality (the parts are smaller so this is easier) so generally a lens designed for crop will perform better than a lens designed for full frame. The 17-40mm L is designed for full frame and performs nearly identically to the 18-55mm kit lens, but is more expensive and worse in nearly every way (though it's color and contrast is said to be slightly better, I don't really care personally).



Not entirely sure what you mean by "perform better", but to the extent you're right re image quality, it's only true if you compare the lenses on a crop body, as Neuro's link demonstrated; lenses designed for ff bodies work better on ff bodies, and the comparison tool at the digital picture repeatedly shows that any given ff lens performs better on a ff body than it does on a crop body; it may also show that ff lenses on ff bodies perform better than their crop equivalents on crop bodies. For instance, many a reviewer/commentator raves about the sharpness of the EF-S 60mm macro which, in comparisons, seems to perform better than the 100mm L on crop bodies; Roger Cicala's blurb on the lens says it's one of the rare lenses that make him wish he used a crop body. And it's certainly an excellent lens; but as I recently found out the hard way (i.e., I bought one, though the digital picture would have demonstrated the point had I bothered to check), while it may be light and convenient, it's certainly not as good as, let alone better than, the 100L on a ff body.

As for "tighter tolerances," even if that's true, something is evidently making a lot of reviewers complain about autofocus accuracy on the Sigma. Fantastic image quality is all very well, but you won't notice it when the focus is off. Have those reading this had problems of focus inaccuracy with the Sigma?


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## Marsu42 (Jan 23, 2014)

Radiating said:


> The 17-40mm L is designed for full frame and performs nearly identically to the 18-55mm kit lens, but is more expensive and worse in nearly every way (though it's color and contrast is said to be slightly better, I don't really care personally).



We should pick up that topic again after you try to shoot in snow, rain and sand for some time with the non-L lens - how sharp is your picture if your lens is broken or after you've gone broke yourself after so many repairs?


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## neuroanatomist (Jan 23, 2014)

Marsu42 said:


> Radiating said:
> 
> 
> > The 17-40mm L is designed for full frame and performs nearly identically to the 18-55mm kit lens, but is more expensive and worse in nearly every way (though it's color and contrast is said to be slightly better, I don't really care personally).
> ...



Then again, how many white box versions of the rebel kit lens can you buy for the price of one 17-40 L?


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## Marsu42 (Jan 23, 2014)

neuroanatomist said:


> Then again, how many white box versions of the rebel kit lens can you buy for the price of one 17-40 L?



Look here, it's Mr. 1dx talking :-> ... I guess it depends on the type of consumer you are, personally I'm not all too comfortable with a throw-away style and am quite attached to my gear. I don't know the crop lens, but imho the L also has nice handling and an internal zoom which is worth something on its own.


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## Lee Jay (Jan 24, 2014)

When I first bought into dSLRs, I bought four lenses:

17-40L
28-135IS
75-300IS
50/1.8

Since then I've bought and sold:
50/1.4
35/2
Sigma 20/1.8
70-200/2.8L IS I
Tamron 1.4x TC
Tamron 2x TC
Canon 1.4x TC II
100/2

And sold from the original purchase:
28-135IS
50/1.8
75-300IS

The one thing I have left from the original purchase is the 17-40L. It's a terrific lens. I like my Sigma 15mm fisheye more and use it much more, but not because of any flaws in the 17-40L, but because I like the field of view, projection and speed of the fish better.

If you don't need a low-light lens, the 17-40L is great. If you don't need sharp corners on full-frame wide open, the 17-40L is great. The corners are much improved at f/5.6 and very, very solid at f/11. The center and the entire APS-c frame is sharp wide open. Focus is fast and sure, handling is excellent.


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## Zv (Jan 24, 2014)

neuroanatomist said:


> Marsu42 said:
> 
> 
> > Radiating said:
> ...



Wow, are we seriously comparing the 17-40L to the 18-55 kit lens? The kit lens is good but it's not in the same category. Despite the obvious differences, I can't for example use the kit lens as an UWA on FF therefore there isn't any way we can compare the two optically. I suppose you could buy a cart load of kits for the price of one 17-40L. But so what? I can also buy a few hundred disposable cameras, still doesn't solve my wide angle needs. 

Why does everyone hate the 17-40L? We can't all afford 16-35LII lenses.


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## slclick (Jan 24, 2014)

Zv said:


> neuroanatomist said:
> 
> 
> > Marsu42 said:
> ...



And unfortunately the price difference does not equate the very minor IQ differences, Yes I've owned both.


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## Lee Jay (Jan 24, 2014)

slclick said:


> And unfortunately the price difference does not equate the very minor IQ differences, Yes I've owned both.



If you buy a 17-40L as a standard zoom for a crop camera now that plenty of EF-s and other crop options are available, well, you're doing it wrong. It's an ultrawide zoom for full-frame.


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## neuroanatomist (Jan 24, 2014)

Lee Jay said:


> If you buy a 17-40L as a standard zoom for a crop camera now that plenty of EF-s and other crop options are available, well, you're doing it wrong. It's an ultrawide zoom for full-frame.



+1 - and that's the point of comparing it to the 18-55/3.5-5.6 IS kit lens or even the 17-55/2.8 IS. Compared to the 17-40L on APS-C, the former delivers not-too-different IQ and the latter delivering better IQ (and an extra stop of light, a broader range, and IS). Yet, many people recommend getting the 17-40L 'in case you go FF maybe someday,' which I think is pretty foolish unless 'someday' is next month.


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## Lee Jay (Jan 24, 2014)

neuroanatomist said:


> Lee Jay said:
> 
> 
> > If you buy a 17-40L as a standard zoom for a crop camera now that plenty of EF-s and other crop options are available, well, you're doing it wrong. It's an ultrawide zoom for full-frame.
> ...



Well, it worked for me, but that was when I bought my 10D, which was before the advent of EF-s. A year and a half later, I bought a 5D so it worked. However, if I had to start over again with crop cameras, I'd do exactly what I did at work and buy a 15-85IS instead.


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## Zv (Jan 24, 2014)

neuroanatomist said:


> Lee Jay said:
> 
> 
> > If you buy a 17-40L as a standard zoom for a crop camera now that plenty of EF-s and other crop options are available, well, you're doing it wrong. It's an ultrawide zoom for full-frame.
> ...



Ah yes those people who have a cheap entry level Rebel camera with a 17-40L stuck on the end! Yup I agree, unless your "other cameras a FF" and currently out of action you have no excuse! Too cheap to buy a FF camera but has enough to show off with an L lens! (A cheap one at that!) you're foolin no one son!


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## pj1974 (Jan 24, 2014)

Lee Jay said:


> neuroanatomist said:
> 
> 
> > Lee Jay said:
> ...



+1

That's why when I entered the DSLR world, there were fewer options out there for APS-C.

I think Canon (& other manufacturers) are dedicated to 'crop sensors' - there are still plenty of good to great lenses being produced exclusively for APS-C DSLRs (ie won't work on FF).

Hence a number of my lenses I chose specifically as EF-S mounts:
the versatile 15-85mm, superb walk-around / 1 lens-solution, with great quality and 
the outstanding Sigma 8-16mm - ultra ultra wide sharp & contrasty too

I frequently advise people to get the lens they need, not 'what they might find useful on a FF'. It might happen to be an EF/ FF lens... but quite often the 'best lens for the current solution' might be an EF-S lens too!

Ok, I also have a 70-300mm L - but that's another story, as none of the other telezooms met my criteria (high optical performance, size/weight to still be portable, full USM, 4 stop IS, and zoom range). 

Paul


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## neuroanatomist (Jan 24, 2014)

dilbert said:


> So you're saying that DxO are criminals because they lied to us saying that the 70-200II is worse than it really is and also because they're saying that the 17-40 is better than it really is?.



No, I'm saying they make mistakes. I do think it's unfortunate and damaging to their credibility that they didn't admit to their mistake with the 70-200 II when called on it, but rather 'circled their wagons', then quietly re-ran their tests and updated the results.



dilbert said:


> Well I guess this means that they're neither biased towards or against Canon...



I don't think they're specifically biased for or against Canon. But I do think their Scores are biased, and that bias currently happens to favor Nikon. Their Sensor Score emphasizes low ISO performance (2 of the three metrics that factor into the sensor score are considered only at ISO 100), and the score is weighted but they don't disclose the weighting. They base their Lens Score on testing in 150 lux, meaning that transmission (T-stop) trumps other measures (sometimes to the exclusion of logic, is the 50/1.8 really a better lens than the 600/4L IS II?), and that lenses tested on bodies with better high ISO performance or more MP (so that noise is reduced when converted to their 8 MP print scale) are given a better score.


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## Radiating (Jan 24, 2014)

sdsr said:


> Radiating said:
> 
> 
> > It's also worth mentioning that lenses designed for crop cameras use tighter tolerances in manufacturing which results in higher image quality (the parts are smaller so this is easier) so generally a lens designed for crop will perform better than a lens designed for full frame. The 17-40mm L is designed for full frame and performs nearly identically to the 18-55mm kit lens, but is more expensive and worse in nearly every way (though it's color and contrast is said to be slightly better, I don't really care personally).
> ...



Right FF Lens on Crop < Crop Lens on Crop < FF Lens on FF 

There are tons of examples of this:

24-105mm on 7D < 15-85mm on 7D < 24-105mm on 5D3

100L on 7D < 60 EF-S on 7D < 100L on 5D3

17-40mm on 7D < 17-55mm 2.8/18-35mm 1.8 on 7D < 17-40mm on 5D3

16-35mm 2.8 on 7D < Sigma 8-16mm on 7D < 16-35mm 2.8 on 5D3 

Although there are some exceptions.



Zv said:


> neuroanatomist said:
> 
> 
> > Lee Jay said:
> ...



Yep that's why I introduced it as "this is something newbies often mix up", the question was to compare a 17-40mm L versus a 18-35mm ART on crop. The 17-40mm L on crop has basically identical performance to the 18-55mm kit lens. while the 18-35mm ART has substantially better performance than either when limiting the comparison to crop only.

Although I've also seen some serious photographers establish that the image quality is ever so slightly better on the 17-40mm over the 18-55mm on crop, so it's still a slight, very slight upgrade. But this argument only made sense when the 17-40mm was 2/3rds the price of the 17-55mm. Now pricing is identical between the two so the choice is clear, unless you need weather sealing or have other special purposes for the 17-40mm on crop, such as sharing the lens with full frame or something else. But I always advise like others to get the lenses that work best now, not later.


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## Radiating (Jan 24, 2014)

neuroanatomist said:


> Radiating said:
> 
> 
> > I have a theory that DXO has been getting specially selected copies with perfect tolerances from Canon. Several of their tests are way better than average. Certainly not impossible, but definitely not "average" from what I've seen.
> ...



Their 17-40mm L is a factory freak (meaning unusually good copy)
Their 50mm 1.2L is also a factory freak

Roger Cicala tested over 30 different copies of the 50mm f/1.2L

and got these results wide open:







The results of DxO Mark returned on the 50mm 1.2L were only achieved by 1 lens that Roger Cicala tested out of 30 copies. There is a massive 25% difference in image quality with a factory freak copy on the 50mm 1.2L, so the fact that DxO Mark got a best out of 30 copy on a lens with a lot of copy variation seems suspicious. This test also seems suspicious, again they are getting a good copy of a lens with a lot of copy variation.

I do agree with you though that while, DxO is a useful source of data, their scores, and ways of ranking products using that data are really nonsensical. It's like adding up a car's interior volume, multiplying by horsepower, and dividing by the price to get a "car mark" score. :

The only DxO Mark score that I like is their low light score, which tells you what the maximum acceptable ISO is for most cameras. Other than that it's only worth looking at the data and ignoring the scores.

But it is nice to get a company that collects data on cameras, and I think people don't appreciate that enough. There's a lot of useful data when you get down to it.


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## ahab1372 (Jan 24, 2014)

Didn't Roger also write something on his website that Imatest _values_ should not compared between different testers/labs? I think you are just doing that. I doubt that DXO and lens rentals have an identical test setup.


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## Rick (Jan 24, 2014)

tron said:


> DXO is such a reliable site... ;D
> 
> http://www.dxomark.com/Lenses/Compare/Side-by-side/Carl-Zeiss-Distagon-2.8-21mm-ZF2-Nikon-on-Nikon-D3X-versus-Carl-Zeiss-Distagon-T-21mm-f-2.8-ZE-Canon-on-Canon-EOS-5D-Mark-II___334_485_326_483



Sad that you believe this makes some kind of statement. For those interested in the facts:

http://www.dxomark.com/en/Reviews/DxOMark-Score 

Having shot with two 5D2s for a couple of years until I replaced one of them with a D3x which I still own, I'd say the overall score differential is about right.


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## Rick (Jan 24, 2014)

Having owned the 16-35, 17-40, 16-35 II in that order and I currently own the Nikkor 14-24G, I'd say the 17-40 is at the bottom of the UWA zoom pack in terms of absolute IQ. Can one make likable images with it? Of course. If I couldn't, that would be saying more about my abilities than the lens'. But let's be honest. The single best "feature" of this lens is price.


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## neuroanatomist (Jan 24, 2014)

dilbert said:


> neuroanatomist said:
> 
> 
> > [But I do think their Scores are biased, and that bias currently happens to favor Nikon. Their Sensor Score emphasizes low ISO performance (2 of the three metrics that factor into the sensor score are considered only at ISO 100), and the score is weighted but they don't disclose the weighting.
> ...



It may be logical but it's still biased. It would be logical to bias a 'car score' toward fuel economy (because everyone wants that, right?), which usually goes hand in hand with smaller engine capacity and lower curb weight. But if you need a high towing capacity or room for three car seats, that bias works against you.

You prove my point when you state that shooting at ISO 1600 is better than ISO 6400. Neither of those is ISO 100. Maybe 95% of your shots are at ISO 100, but the majority of my shots are higher than that. If my average ISO is 1600, and 'sensor A' performs better than 'sensor B' at ISO 100, but worse at ISO 1600, then DxO's biased Score is not helpful to me. 

Bias isn't always bad...as long as the nature of the bias is known. But a biased score with unspecified weightings is not useful. Do you really believe that a D800 delivers better IQ than a Phase One IQ180? 



dilbert said:


> > They base their Lens Score on testing in 150 lux, meaning that transmission (T-stop) trumps other measures (sometimes to the exclusion of logic, is the 50/1.8 really a better lens than the 600/4L IS II?), and that lenses tested on bodies with better high ISO performance or more MP (so that noise is reduced when converted to their 8 MP print scale) are given a better score.
> 
> 
> 
> ...



*"DxO measure a lens in terms of its ability to reproduce an image."*. Yes, they do - and as I've repeatedly stated, their measurements are useful (when correct). Of course they're not measuring IS or build quality for lenses, any more than they measure fps or AF performance for their sensor score - no one has suggested that, and your reference to it is a red herring. 

But, while DxO _measures_ lenses in terms of optical performance, the DxO _Lens Score_ has very little relationship to those measurements, but instead is based primarily on *performance in 150 lux illumination* (e.g., dim warehouse light levels). If their Score primarily represents a lens' 'ability to reproduce an image' does it make sense to you that the 50/1.8 II can reproduce a better image than the 600/4 II? Would you agree that lens performance generally improves when a lens is stopped down a bit? If so, does it make sense that the 50/1.8 II is, "Best at 50mm f/1.8," as DxO states right next to the Lens Score? 

Furthermore, sensor performance influences the Lens Score, as in tron's example of the same Zeiss lens in Canon vs. Nikon mount, with optical metrics the same (or very marginally better on the Canon) scoring 10% higher on Nikon. 

Sure, you can define "better" as better for shooting in a dimly lit warehouse. But that makes little sense as a basis for a Score used to compare lenses - an f/1.8 lens doesn't 'reproduce an image' better than an f/4 simply by virtue of transmitting more light. Image Quality is not defined primarily by a lens' maximum T-stop. The Lens Score is biased and misleading, _especially_ when DxO sticks that score on top of a list of optical metrics, which implies those metrics are somehow 'summarized' by that score when that's not at all the case. 

I like DxO, I use their RAW converter as part of my workflow, and their sensor and lens measurements are useful, too. But...their *B*iased *S*cores are just that...BS = bovine scat = cow excrement.


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## The Flasher (Jan 24, 2014)

Maybe I had a bad batch copy, but this lens was limiting in so many ways, including mushy images, esp in corners, awful distortion, f/4 was a roadblock in a lot of applications and not quite wide enough. The pros included its low price, light weight, and relatively high resale value.

I cross-graded to a used 16-35 2.8 ver. I for slightly less crappy image quality but extra stops and 1mm width.


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## Marsu42 (Jan 24, 2014)

Rick said:


> Having owned the 16-35, 17-40, 16-35 II in that order and I currently own the Nikkor 14-24G, I'd say the 17-40 is at the bottom of the UWA zoom pack in terms of absolute IQ.



Not that it'd really matter, but the 17-40L was reported to be an improvement over the 16-35L1 at the time.


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## Cariboucoach (Jan 24, 2014)

Zv said:


> neuroanatomist said:
> 
> 
> > Lee Jay said:
> ...



I've read that it is better to get good glass on a cheaper camera than the cheap glass on an expensive camera. So now the person who takes that advice is being made fun of?


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## slclick (Jan 24, 2014)

Cariboucoach said:


> Zv said:
> 
> 
> > neuroanatomist said:
> ...



Yes and no. Certain lenses are optimized for the sensor size and certain FL's are considered 'standard' or common. Take for example the 40 pancake, it's an odd FL on a 1.6 crop but a great wide/normal on a FF.

I think a great example of getting better glass on a lesser body would be a 17-55 EF-S on a T2i for example.


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## Marsu42 (Jan 24, 2014)

Cariboucoach said:


> I've read that it is better to get good glass on a cheaper camera than the cheap glass on an expensive camera. So now the person who takes that advice is being made fun of?



Both should be bought to *match* each other - the consideration to make is that there are basically two sensor types (ff & crop), but a nearly linear choice of lens quality. The ef type is not always "better" than ef-s and vice versa, and in the tele range it's ef anyway no matter the sensor type. Consider this classic:

Pro DSLR + Cheapo Lens vs "Cheapo" DSLR + Pro Lens


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## neuroanatomist (Jan 24, 2014)

dilbert said:


> I'm willing to bet that the lighting level they choose to use is for a specific purpose and not just some randomly picked number.
> 
> For example, maybe it is easier for them to detect the difference between f-stop and t-stop at that level. Maybe there is less internal reflections and flaring at that level. And so on. Whilst we don't know why they chose that level of illumination, I'd wager that it isn't an arbitrary choice.


Of course it's not a randomly picked number, and they state why they picked it: "_...we choose the scene illumination to be 150 lux and the exposure time 1/60s. Such conditions were chosen as we believe low-light performance is particularly important for today’s photography and it is also important for photographers to know how well lenses perform at widest aperture._" The point is that choosing a low level of illumination like that introduces a *bias* into their scores, and it's a non-obvious bias given the way the scores are presented (yes, you can find out about the 150 lux testing, but you have to look for it). 

Even the explanation for their bias is applied in a biased (and undisclosed) manner. They state that, "...it is also important for photographers to know how well lenses perform at widest aperture," and the implication is that since the 50/1.8 scores higher than the 600/4, for example, the 50/1.8 performs better at f/1.8 than the 600/4 at f/4.



dilbert said:


> It is entirely possible that a 50/1.8 can reproduce an image better than a 600mm lens. Look at all of the noise people have made about Zeis's 55mm recent announcement. Just because a lens is bigger or heavier or has a longer focal length doesn't mean it is better at reproducing an image.


According to DxO's own data, the 600 II is sharper, has less distortion, less vignetting, and less chromatic aberration. The 600/4 also loses less light relative to it's f/number than the 50/1.8, i.e. the 600's max T-stop is closer to it's max f/stop than is the case for the 50/1.8. So, on every measure of optical performance _except_ absolute light transmission, the 600 II is a better lens. But the 50/1.8 gets a better Score. So…a higher DxO Score is saying that a faster lens is "better" simply because it's faster, as if people are unable to figure that out from the f/1.8 vs. the f/4 spec. Even people who think they can shoot video with a lens that doesn't have a camera attached to it are probably able to understand that an f/1.8 lens will transmit more light than an f/4 lens, and hopefully don't need DxO's BS to tell them that. 

As for it being, "_...entirely possible that a 50/1.8 can reproduce an image better than a 600mm lens,_" you can easily see how much better the 50/1.8 II at f/1.8 reproduces an image, compared to the 600mm f/4L IS II at f/4. Just look for yourself. : : :

Incidentally, according to DxOMark, the Canon 300mm f/2.8L IS II is:

sharper than the Zeiss Otus 55mm f/1.4
has less distortion than the Zeiss Otus 55mm f/1.4
has less vignetting than the Zeiss Otus 55mm f/1.4
has less chromatic aberration than the Zeiss Otus 55mm f/1.4

…but still, the Zeiss Otus 55mm f/1.4 gets a significantly higher score. Why? Because it's f/1.4…and in world of DxOMark's BS, that automatically makes it "better".


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## mrsfotografie (Jan 24, 2014)

Marsu42 said:


> Cariboucoach said:
> 
> 
> > I've read that it is better to get good glass on a cheaper camera than the cheap glass on an expensive camera. So now the person who takes that advice is being made fun of?
> ...



I enjoyed that!


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## neuroanatomist (Jan 25, 2014)

dilbert said:


> neuroanatomist said:
> 
> 
> > ...
> ...



Maybe. That must explain all the Internet love for the 50/1.2L, everyone says it's such a great lens.


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## mackguyver (Jan 25, 2014)

neuroanatomist said:


> Maybe. That must explain all the Internet love for the 50/1.2L, everyone says it's such a great lens.


LOL and I just don't get why my 50L is such crap. I bought it to take macro photos wide open and it just sucks. It's almost as bad as the 85L that I bought to cover football games, the 300 2.8 I bought as a compact lightweight travel lens, and the 180 macro I bought to shoot indoor hockey games. I guess I should've checked DxO's "Use Case Scores" before I bought them      .


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## tron (Jan 26, 2014)

mackguyver said:


> neuroanatomist said:
> 
> 
> > Maybe. That must explain all the Internet love for the 50/1.2L, everyone says it's such a great lens.
> ...


You forgot the use of your 24mm lens for birding ;D


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## Canon1 (Jan 26, 2014)

tron said:


> You forgot the use of your 24mm lens for birding ;D



I've seen some amazing wide angle bird photography with extremely unique perspectives that include the amazing habitats they live in.

I get your jokes... and they are funny... but sometimes taking the "wrong" lens with you can help you to produce some really unique images.


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## tcmatthews (Jan 26, 2014)

Canon1 said:


> I get your jokes... and they are funny... but sometimes taking the "wrong" lens with you can help you to produce some really unique images.



Tell me if you take the "wrong" lens and produce "unique images" is it really the "wrong" lens?


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## slclick (Jan 26, 2014)

tcmatthews said:


> Canon1 said:
> 
> 
> > I get your jokes... and they are funny... but sometimes taking the "wrong" lens with you can help you to produce some really unique images.
> ...



If a leaf shutter opens in the forest with no one around, does it really take a photograph?


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## tcmatthews (Jan 26, 2014)

Cariboucoach said:


> Zv said:
> 
> 
> > neuroanatomist said:
> ...



I am a proponent of using good glass on a cheep camera but it has to make sense. The 17-40L on a rebel is a waist. The camera can take much better pictures with a good EF-s lens. The 17-40L lacks IS it is relatively slow for crop. If you are going to get a full frame L lens for a crop camera get one of the 24-x lenses, and then buy a Ef-s Ultra wide. 24-x is fine for an outdoor zoom in wide open places. Save buying the ultra-wide full frame lens for when you buy a full frame camera.

All of the telephoto lens make sense. So a 70-200L or 70-300L should be on all Rebel users list if they plan on moving to full frame.

But that is just my opinion.


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## tcmatthews (Jan 26, 2014)

I have in general been avoiding all DxO Mark threads. I find the lens reviews at best a comedy of errors at worst egregious miss characterizations. They sometimes bash lens for flaws of the cameras they are testing it on. All in in all it is just better to ignore them. 

The only camera they have tested the Sony E10-18f4 on is the Nex7. Spent a huge amount of time complaining of soft corners and color fringing. The Nex7 has a well documented problem with wide angle lens because of a micro-lens design flaw and the never once mention that. They have also never bothered to test it on any other Sony Nex cameras.

The Sigma DN 19 and DN 30 have only been reviewed on the absolute worst m43 camera. They have terrible scores but are fantastic lens for the price. 

Last time I checked the Tamron 28-75 had higher marks in Both the Sony and Nikon mount.


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## mrsfotografie (Jan 26, 2014)

tcmatthews said:


> If you are going to get a full frame L lens for a crop camera get one of the 24-x lenses, and then buy a Ef-s Ultra wide. 24-x is fine for an outdoor zoom in wide open places. Save buying the ultra-wide full frame lens for when you buy a full frame camera.



That makes sense, and incidentally is exactly what I did when I decided to buy glass to prepare for the move to full frame later on. I had the Tokina 12-24 f/4 DX at the time, a bombproof piece of kit that was!


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## Marsu42 (Jan 26, 2014)

mrsfotografie said:


> tcmatthews said:
> 
> 
> > If you are going to get a full frame L lens for a crop camera get one of the 24-x lenses, and then buy a Ef-s Ultra wide. 24-x is fine for an outdoor zoom in wide open places. Save buying the ultra-wide full frame lens for when you buy a full frame camera.
> ...



I also agree - the important thing is that the 17-40L on crop is "good enough" to be very usable, so you can either get it before moving to ff or dual-use it on crop & ff.


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## Canon1 (Jan 26, 2014)

tcmatthews said:


> Canon1 said:
> 
> 
> > I get your jokes... and they are funny... but sometimes taking the "wrong" lens with you can help you to produce some really unique images.
> ...



You catch on quick.


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