# PhotoZone Review: 16-35 f/2.8L III



## ahsanford (Nov 13, 2016)

PZ's read on the 16-35 f/2.8L III:

http://www.photozone.de/canon_eos_ff/992-canon1635f28mk3?start=1

TDP's painful vignetting figure is indeed corroborated here: _4.61 stops_ at 16mm f/2.8. 

- A


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## Viggo (Nov 13, 2016)

Wow, that's pretty bad vignetting! They almost can't call it a 2.8 or even a full frame lens, lol.

I can't remember the 16-35 f4 IS being this bad, but I noticed it was not great...


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## YuengLinger (Nov 13, 2016)

Thanks, ahsanford for posting this. Ugh.

Seems to be a common theme. Aggravating.

Price is a factor, absolutely. When you buy a Yaris, you accept the road noise. When you step up to Lexus, no.

If the numbers are correct, this is a terrible blow for those of us who don't put the subject dead center in every composition at f/2.8. I'm so glad I didn't rush to sell my f/4 to have $$ to put towards this.

Hope the 24-105mm is a better improvement!


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## Click (Nov 13, 2016)

Thanks for posting, ahsanford.


I totally agree with you, YuengLinger.


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## rfdesigner (Nov 13, 2016)

ahsanford said:


> PZ's read on the 16-35 f/2.8L III:
> 
> http://www.photozone.de/canon_eos_ff/992-canon1635f28mk3?start=1
> 
> ...



The old one is only 2.8 stops according the the same source.

http://www.photozone.de/canon_eos_ff/435-canon_1635_28_5d?start=1

For those who want the lens as a wide portrait lens, OOF background (& corners) why would they buy the new lens?


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## DominoDude (Nov 13, 2016)

<sarcasm>
*Congratulations, Canon, on your first EF-S L-glass!*

Must be the first time an EF-S fits the EF mount. Did you have trouble deciding if you wanted to light up the entire image circle for a FF sensor, or did you just decide to categorize it as "vignetting"?
</sarcasm>


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## ahsanford (Nov 13, 2016)

And Dustin Abbott agrees on the vignetting:

http://www.canonrumors.com/forum/index.php?topic=31274.0
(link to the full review is there, but I thought I'd send comments about that review to that thread, which Dustin is certainly monitoring and replying to.)

He claims twice the vignetting when shot wide open than the Tamron 15-30 f/2.8 VC, which is right in line with what TDP found.

The question then becomes: who gets punished by 16mm + f/2.8 having so much vignetting? I would presume astro would hate having to boost the exposure so much to correct this, and environmental portraiture folks will likely have to keep folks somewhat central (but at 16mm with faces you'd kind of need to do that anyway). 

Events? Would concert or wedding reception shots take a hit from this?

Sports folks should manage, I'd think. I see a 16-35mm f/2.8 commonly used at (American) football games where the coaches shake hands in a mob of people after the final whistle. Also perhaps hoops from the baseline to get the full width of the baseline in view (everyone watching a shot). Full disclosure -- I'm no sports guy, please pipe up if you have thoughts on this.

Non-astro landscapers shouldn't care.

- A


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## AdamBotond (Nov 13, 2016)

That vignetting is hard to digest indeed. Especially with version II having "only" 2,6 EV at 2.8, its hard to justify 4,6 EV vignetting at this price point. Ironically, people were complaining about the lack of sharpness in the edges of version II. Finally, they got sharpness through the entire frame in III, but they got almost twice as much vignetting, making improved edge sharpness look much less attractive. 

Granted, by stopping down vignetting will disappear. However, whoever is willing to pay premium for 2.8 , is certainly intending to use it wide open, otherwise F4 IS would be just fine for much less money. 

I'm not much into tech details, but was wondering what caused this challenge for Canon as once they had vignetting much better under controll in version II.


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## Alex_M (Nov 13, 2016)

Adam, that's almost 4 times as much vignetting as the difference is nearly 2ev. not sure what Canon engineers were thinking about 



AdamBotond said:


> That vignetting is hard to digest indeed.... Finally, they got sharpness through the entire frame in III, but they got *almost twice as much vignetting*, making improved edge sharpness look much less attractive...


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## hendrik-sg (Nov 13, 2016)

This vignetting is a nogo indeed. 

This seems to be the easiest way to get good sharpness vaalues, just darken the less sharp outer regions. this lens has worse transmission than the F4 IS verion in the outer regions, then i would better like to have IS (and keep 1/2 the money).

-4EV means, it's a T>5.6 lens at the corners, this should not cost 2k$


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## Random Orbits (Nov 14, 2016)

hendrik-sg said:


> This vignetting is a nogo indeed.
> 
> This seems to be the easiest way to get good sharpness vaalues, just darken the less sharp outer regions. this lens has worse transmission than the F4 IS verion in the outer regions, then i would better like to have IS (and keep 1/2 the money).
> 
> -4EV means, it's a T>5.6 lens at the corners, this should not cost 2k$



The vignetting is comparable to less than the 16-35 f/4 IS at comparable apertures. It's probably due to design constraints. Want a well correct lens? Then choose between a filterable design with heavy vignetting or a convex front element (a la the 15-30) that is not filterable and has less vignetting. No one is making you buy it; you have a choice.


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## Alex_M (Nov 14, 2016)

Else, Canon could have designed the lens with filterable but larger, say, 86mm front element. That would certainly improve viignetting levels in extreme corners but increase cost, size and weight of the lens. 



Random Orbits said:


> hendrik-sg said:
> 
> 
> > This vignetting is a nogo indeed.
> ...


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## YuengLinger (Nov 14, 2016)

Random Orbits said:


> hendrik-sg said:
> 
> 
> > This vignetting is a nogo indeed.
> ...



What a revelation! This adds incredible insights to the conversation! Thank you! :


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## Random Orbits (Nov 14, 2016)

YuengLinger said:


> Random Orbits said:
> 
> 
> > hendrik-sg said:
> ...



Anytime. Of course, you didn't Dustin to tell you the corners vignetted heavily -- that info was already out (TDP), unless you were thinking that copy-to-copy variation could account for that much difference in vignetting performance. :


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## YuengLinger (Nov 14, 2016)

Random Orbits said:


> YuengLinger said:
> 
> 
> > Random Orbits said:
> ...



I take individual reviews, even reputable ones, with a grain of salt, waiting for a consensus to form.

LensRental is great because they work with many units.

Personal example: I just sent an 80D back to the retailer because AI Servo was abysmal. Received a new one and see all the AF functions as very good.


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## hendrik-sg (Nov 14, 2016)

Despite i am a technician with some physical knowledge, i can not judge about the compromises which have really been done, but if it has to be stopped down only one stop (to adjust the brightness of the center to the brightness of the corners) the lens becomes obsolete

I buy fast lenses for their light gathering capabilities and i do not want to have to push the corner by this amount


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## LordofTackle (Nov 14, 2016)

hendrik-sg said:


> Despite i am a technician with some physical knowledge, i can not judge about the compromises which have really been done, *but if it has to be stopped down only one stop (to adjust the brightness of the center to the brightness of the corners) the lens becomes obsolete*
> 
> I buy fast lenses for their light gathering capabilities and i do not want to have to push the corner by this amount



Well, in that case almost every fast lens ever made is obsolete (by your definition) and you can throw them out of the window


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## BeenThere (Nov 14, 2016)

I'm not a lens designer, but there are always trades to make. Perhaps vignette and edge of frame sharpness is one of those trades. It seems all the wide angles have this issue: either soft edges or a lot of vignette in the corners? A "lot" is a relative term and some makers get better overall results than others. For instance the Tamron 15-30 is a little softer than the new 16-35 Canon (over the whole frame to my eye), yet the vignette of the Tamron is not as bad. Which would you prefer?


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## ahsanford (Nov 14, 2016)

LordofTackle said:


> hendrik-sg said:
> 
> 
> > Despite i am a technician with some physical knowledge, i can not judge about the compromises which have really been done, *but if it has to be stopped down only one stop (to adjust the brightness of the center to the brightness of the corners) the lens becomes obsolete*
> ...



I catch the  and appreciate the reality of wide aperture lenses, but can you honestly tell me of a lens that was 'sequeled' by Canon (same FL range, same max aperture) that got *this* much worse in one metric?

- A


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## ahsanford (Nov 14, 2016)

BeenThere said:


> I'm not a lens designer, but there are always trades to make. Perhaps vignette and edge of frame sharpness is one of those trades. It seems all the wide angles have this issue: either soft edges or a lot of vignette in the corners? A "lot" is a relative term and some makers get better overall results than others. For instance the Tamron 15-30 is a little softer than the new 16-35 Canon (over the whole frame to my eye), yet the vignette of the Tamron is not as bad. Which would you prefer?



I am not a lens designer, but surely they could have made other calls with the front element and retained front filterability, correct? I'm not saying the filters would be as readily available or inexpensive, but they could have put in a larger front element, couldn't they?

- A


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## LordofTackle (Nov 14, 2016)

ahsanford said:


> LordofTackle said:
> 
> 
> > hendrik-sg said:
> ...



I can't (or in other words are too lazy to take a look ) and I'm totally with you concerning the atrocious 4 stops vignette of that lens!
But he was saying that every lens that has one or more stop vignette is obsolete (at least thats how I read his post). And by that argumentation every fast lens that I know of is obsolete (including Otus 28, 55 and 85, Sigma Art 1.4 35 and 50, Ef 35 1.4 II, etc...)


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## rfdesigner (Nov 14, 2016)

hendrik-sg said:


> -4EV means, it's a T>5.6 lens at the corners, this should not cost 2k$



No it doesn't it's much much worse than that.

-4.6ev means the light in the corners is 4.6 stops less than the light in the middle.

that means f2.8 in centre, so 4.6 stops beyond from that is.... ~ F13



What I want to see is corner Boke at 16mm wide open.. I think it might be missing.


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## Sharlin (Nov 14, 2016)

Like someone on /r/photography said, now there's finally a real reason for having to push five stops in post


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## hendrik-sg (Nov 14, 2016)

rfdesigner said:


> hendrik-sg said:
> 
> 
> > -4EV means, it's a T>5.6 lens at the corners, this should not cost 2k$
> ...



this i thougt myself, but it seems 2 EV vignetting is 50% or 1 stop loss, if you do the maths at lenstip's results. You can see this on TDP as well, if you stop down a lens 2.8 > 4.0, it can improve almost 2 stops, which would mean it has more transmission at 4.0 than at 2.8, which would be really weird. (this is the way how i found out)


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## rfdesigner (Nov 15, 2016)

hendrik-sg said:


> rfdesigner said:
> 
> 
> > hendrik-sg said:
> ...



I hate to quote DxOmark at anyone but here goes

"What does DxOMark measure?

DxOMark measures light vignetting by imaging an evenly-lit white target. Pixel values are retrieved from all parts of the image. The ratio of these values over the maximum value (usually the value at the image center) found in the image gives the vignetting measurement for each pixel. Vignetting is expressed in exposure value (EV): a variation of 1EV is an attenuation of a factor of 2."

i.e. for 4.6EV you have an attenuation factor of 2^4.6 or 96% fall off.

There should be no square roots going on, if half the photons fall in the corner relative to the centre the ADC will see this as half the reading and that equates to a 1EV fall off.

I also agree the [email protected] and the [email protected] don't look at all possible which is why I suspect that there is something else going on.. perhaps something to do with fall off caused by oblique lighting in the corners, or even some hidden pre-processing.

To prove this to myself I measured the vignetting on my own 50STM the other day: I used DPP, set all processing to off (no vignetting correction), set it to "linear" then measured the pixel values in the centre and all corners.

I measured a fall off of ~75% or -2EV. Photozone has it as -2.56, DxO is at ~-2.5 (in the data for wide open, their headline figure is different)

I think that's close enough to prove it's not 2EV for 50% fall off, in other words 4.6EV really is 96% fall off.. and for whatever strange reason the data suggests it gets more signal at f4.0 in the corners.. which can't be right, but that's what the data says


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## kaffikopp (Nov 20, 2016)

Regarding everyone getting up in arms about the vignetting, why would this be a dealbreaker for astro when according to TDP, the go-to lens for astrophotographers these days, the Samyang 14mm f/2.8 has about the same amount? Link

Sure, the Samyang costs a fraction of the new Canon L lens, but if we ignore price for a moment and just look at real world usage, the end result is the same with both lenses: having to push the corners by several stops. From what I've seen so far, the coma performance of the L is pretty impressive, on par with or maybe even surpassing the Samyang. You also get better overall IQ, less distortion, AF, L-grade build quality and the versatility of a zoom.

Now I haven't used either of these lenses myself, but was planning on the 16-35 III to be my next lens purchase until I learned of the massive vignetting. However, as already explained, if it's not an issue for astro with the Samyang, why would it be with this lens?


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## raptor3x (Nov 20, 2016)

kaffikopp said:


> Regarding everyone getting up in arms about the vignetting, why would this be a dealbreaker for astro when according to TDP, the go-to lens for astrophotographers these days, the Samyang 14mm f/2.8 has about the same amount? Link



It's interesting that TDP, Lenstip, and Photozone all have very different measurements for vignetting on the Samyang 14 2.8 at ~4ev, ~2.3ev, and ~3.3ev respectively. Seems like some sort of methodology issue.


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## rfdesigner (Nov 20, 2016)

raptor3x said:


> kaffikopp said:
> 
> 
> > Regarding everyone getting up in arms about the vignetting, why would this be a dealbreaker for astro when according to TDP, the go-to lens for astrophotographers these days, the Samyang 14mm f/2.8 has about the same amount? Link
> ...



see: http://www.canonrumors.com/forum/index.php?topic=31337.0


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## raptor3x (Nov 20, 2016)

rfdesigner said:


> see: http://www.canonrumors.com/forum/index.php?topic=31337.0









Thanks, good catch.


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## neurorx (Nov 20, 2016)

So how does the 16-35mm III compare to other similar lenses then? I was considering this one for landscape and astrophotographery.


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## StudentOfLight (Nov 20, 2016)

kaffikopp said:


> Regarding everyone getting up in arms about the vignetting, why would this be a dealbreaker for astro when according to TDP, the go-to lens for astrophotographers these days, the Samyang 14mm f/2.8 has about the same amount? Link
> 
> Sure, the Samyang costs a fraction of the new Canon L lens, but if we ignore price for a moment and just look at real world usage, the end result is the same with both lenses: having to push the corners by several stops. From what I've seen so far, the coma performance of the L is pretty impressive, on par with or maybe even surpassing the Samyang. You also get better overall IQ, less distortion, AF, L-grade build quality and the versatility of a zoom.
> 
> Now I haven't used either of these lenses myself, but was planning on the 16-35 III to be my next lens purchase until I learned of the massive vignetting. However, as already explained, if it's not an issue for astro with the Samyang, why would it be with this lens?


Samyang's vignette is not as bad and it is a wider focal length so enables a longer exposure before trailing. The goto lens is in fact the Tamron 15-30mm f/2.8:


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