# TDP Review of the RF 15-35 f2.8 L IS



## Viggo (Oct 14, 2019)

Bryan posted his review.

I still can’t get over the vignetting of Canons uwa’s...

https://www.the-digital-picture.com/Reviews/Canon-RF-15-35mm-F2.8-L-IS-USM-Lens.aspx


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## ethanz (Oct 15, 2019)

He seemed to love it though Viggo...


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## josephandrews222 (Oct 15, 2019)

I have yet to purchase a body suitable for this lens.

When I make that purchase, this lens will be 'tied for first' as far as lens additions are concerned.


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## mb66energy (Oct 15, 2019)

Viggo said:


> Bryan posted his review.
> 
> I still can’t get over the vignetting of Canons uwa’s...
> 
> https://www.the-digital-picture.com/Reviews/Canon-RF-15-35mm-F2.8-L-IS-USM-Lens.aspx


Thanks for the link!
Maybe vignetting is the least problematic lens aberration from the point of view of Canon. And I think it is
easy to correct in most situation except if DR is exhausted in some situations.

IMO the most impressive "feature" is the low impact of artifacts just @f/11 which is necessary
in bright sunlight and I am shure it will be decent with the sun inside the frame. And an UWA which does
not work with the sun inside the frame does not work.


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## Viggo (Oct 15, 2019)

Yeah, I’ll take vignetting over fringing etc any day for sure. But, man, 5 stops? F2.8 in the center and f16 in the corners , suddenly pushing 5 stops isn’t so ridiculous.

TDP also says the RF50 has a serious amount of vignetting, but it’s always measured in a seriously worst case scenario so at normal focusing distances I see very low vignetting from the 50.

So I think if one includes foreground quite close it might not show anywhere near five stops, but focus at infinity and shooting anything less than f8 and I suspect it willan issue, and what about filter use? A 10 stop on this lens will be very interesting to see the results with.

does anyone here have the 16-35 III and can comment on the vignetting in actual use?


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## BillB (Oct 15, 2019)

Viggo said:


> Yeah, I’ll take vignetting over fringing etc any day for sure. But, man, 5 stops? F2.8 in the center and f16 in the corners , suddenly pushing 5 stops isn’t so ridiculous.
> 
> TDP also says the RF50 has a serious amount of vignetting, but it’s always measured in a seriously worst case scenario so at normal focusing distances I see very low vignetting from the 50.
> 
> ...


Don't have the 16-35 III, but worst case is likely 16mm @ f2.8. So one question as a starting point is how often are you going to be shooting at 16mm and f2.8 where you are going to be worried about the corners?


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## bhf3737 (Oct 15, 2019)

Viggo said:


> does anyone here have the 16-35 III and can comment on the vignetting in actual use?


I guess the wide open indoor architecture would be a good use-case to test this lens' capability.
This review video takes the lens to a cathedral and shoots wide open @15mm f/2.8 (from around 8 minute on): The conclusion was that the corners get a bit soft and some vignetting but not to the level that could make the image unusable.


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## ethanz (Oct 15, 2019)

bhf3737 said:


> I guess the wide open indoor architecture would be a good use-case to test this lens' capability.
> This review video takes the lens to a cathedral and shoots wide open @15mm f/2.8 (from around 8 minute on): The conclusion was that the corners get a bit soft and some vignetting but not to the level that could make the image unusable.



Yeah he barely mentions the vignetting in that video. So Viggo I think you'll be fine. Just go buy it.


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## Viggo (Oct 15, 2019)

bhf3737 said:


> I guess the wide open indoor architecture would be a good use-case to test this lens' capability.
> This review video takes the lens to a cathedral and shoots wide open @15mm f/2.8 (from around 8 minute on): The conclusion was that the corners get a bit soft and some vignetting but not to the level that could make the image unusable.


I had already actually seen that video


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## Viggo (Oct 15, 2019)

BillB said:


> Don't have the 16-35 III, but worst case is likely 16mm @ f2.8. So one question as a starting point is how often are you going to be shooting at 16mm and f2.8 where you are going to be worried about the corners?


If I had that lens I would always be shooting wide open or buy the f4 L IS again  and with the AF spread using the R I would be using corners more also.


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## Viggo (Feb 9, 2020)

Just started thinking about getting the 15-35 again, and wanted to know if people who have used it a bit care to share some examples of corrected and uncorrected corners at 2.8? Or link to some raws I could play with .


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## uri.raz (Feb 9, 2020)

mb66energy said:


> Maybe vignetting is the least problematic lens aberration from the point of view of Canon. And I think it is easy to correct in most situation except if DR is exhausted in some situations.



There were threads discussing how poor Canon images look when underexposed 6 stops with ugly banding etc, specifically when compared to Sony. With the RF 15-35mm f/2.8L vignetting 4-5 stops in the corners, owners will get all the ugly chroma noise, banding, etc there.

If the sensor has 11 bits of DR at IS 1600, then 4 stops of vignetting means the corners get only 7.

For static scenes this could be handled with exposure compensation / exposure blending, but not always.


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## Viggo (Feb 9, 2020)

uri.raz said:


> There were threads discussing how poor Canon images look when underexposed 6 stops with ugly banding etc, specifically when compared to Sony. With the RF 15-35mm f/2.8L vignetting 4-5 stops in the corners, owners will get all the ugly chroma noise, banding, etc there.
> 
> If the sensor has 11 bits of DR at IS 1600, then 4 stops of vignetting means the corners get only 7.
> 
> For static scenes this could be handled with exposure compensation / exposure blending, but not always.


In all fairness, there is no banding etc with the 1dx2, 5d4 and R sensor


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## PiezoSwitch (Feb 9, 2020)

Interestingly the new RF 70-200/2.8 suffers from vignetting as well. Based on the review from the Optical Limits website at 200mm and f/2.8 the edges are -2.6 stops. If you're shooting higher ISOs noise can definitely become an issue.


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## Viggo (Feb 9, 2020)

PiezoSwitch said:


> Interestingly the new RF 70-200/2.8 suffers from vignetting as well. Based on the review from the Optical Limits website at 200mm and f/2.8 the edges are -2.6 stops. If you're shooting higher ISOs noise can definitely become an issue.


Indeed.... I’m very disappointed ... to have a 24-70 F2.8 with two stops more vignetting than a 50 f1.2? And the 50 already has too much shading...
Not superb...


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## BeenThere (Feb 9, 2020)

There are no perfect lenses. Always the designer must make trade-offs and compromises. It appears that Canon designers are letting go of the vignetting in order to more nearly optimize sharpness, coma and CA. For some, this will be the correct move. Astrophotographers however will decent. Primes from third parties are probably still best for this application, but currently only in EF mount.


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## Viggo (Feb 9, 2020)

BeenThere said:


> There are no perfect lenses. Always the designer must make trade-offs and compromises. It appears that Canon designers are letting go of the vignetting in order to more nearly optimize sharpness, coma and CA. For some, this will be the correct move. Astrophotographers however will decent. Primes from third parties are probably still best for this application, but currently only in EF mount.


You’re probably right. I hope it’s because Canon has got some brutal new sensor tech that make it a non-issue to fix in post. One can dream, right?


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## brad-man (Feb 9, 2020)

I'm waiting for the review of the RF f/4 version that has yet to be released


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## YuengLinger (Feb 10, 2020)

Viggo said:


> Just started thinking about getting the 15-35 again, and wanted to know if people who have used it a bit care to share some examples of corrected and uncorrected corners at 2.8? Or link to some raws I could play with .



Have you seen Christopher Frost's review? The vignetting and distortion examples begin at 5 mins 30 secs.


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## Del Paso (Feb 10, 2020)

I've just decided to keep my inexpensive and excellent EF 4/16-35.
For the money saved, I'll think I'll buy the EF 11-24...
Disappointed...far too much vignetting.


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## Viggo (Feb 10, 2020)

YuengLinger said:


> Have you seen Christopher Frost's review? The vignetting and distortion examples begin at 5 mins 30 secs.



yeah I saw that earlier, and it didn’t really convince me it’s worth it. I also saw his review of the 24-70, a lot of vignetting and mustache distortion. Didn’t really compare to the EF 24-70 mk2, but I couldn’t remember it being very poor with vignetting and although barrel distortion, no mustache? Correct me if I’m wrong. So for twice the money you get IS and worse optical performance except marginally better sharpness? Hmm... and with IBIS coming, is there enough reason to get the RF over the EF?


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## YuengLinger (Feb 10, 2020)

Viggo said:


> yeah I saw that earlier, and it didn’t really convince me it’s worth it. I also saw his review of the 24-70, a lot of vignetting and mustache distortion. Didn’t really compare to the EF 24-70 mk2, but I couldn’t remember it being very poor with vignetting and although barrel distortion, no mustache? Correct me if I’m wrong. So for twice the money you get IS and worse optical performance except marginally better sharpness? Hmm... and with IBIS coming, is there enough reason to get the RF over the EF?



I think you are asking all the right questions! But didn't this heavy vignetting get started with the ef 16-35mm f/2.8L III? Is it really due to chasing sharpness?


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## Viggo (Feb 11, 2020)

YuengLinger said:


> I think you are asking all the right questions! But didn't this heavy vignetting get started with the ef 16-35mm f/2.8L III? Is it really due to chasing sharpness?


Yeah, I was thinking about a UWA faster than the excellent f4 IS, but the heavy vignetting of the 16-35 mk3 killed it for me. I hate distortion and vignetting the most of all aberations so yeah... ca sucks too, and perhaps distortion is worst and vignetting and CA share second place.

and I think the disappointment is bigger when it’s the new RF glass and I had such high expectations, and especially since I have the two f1.2 primes.

hopefully it’s a bit of the same story as with the 50, vignetting doesn’t look good TDP, but at different focusing distances it’s not that bad at all.


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## Joules (Feb 11, 2020)

The R and RP use special micro lenses to deal better with the small distance between the sensor and lens, right? It's the reason Canon calls the respective sensors 'new', despite clearly being the 5D IV and 6D II sensor underneath the filters/lenses. 

I wonder if Canon could have some room to make further advancements in the micro lenses, to reduce vignetting? Especially with IBIS coming now, vignetting could actually become more noticeable. Do we have any idea if the beam splitting from the low pass filter also has an impact on vignetting, and if so, if a new low pass filter like the one from the 1DX III could help?


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## koenkooi (Feb 11, 2020)

Joules said:


> The R and RP use special micro lenses to deal better with the small distance between the sensor and lens, right? It's the reason Canon calls the respective sensors 'new', despite clearly being the 5D IV and 6D II sensor underneath the filters/lenses.
> 
> I wonder if Canon could have some room to make further advancements in the micro lenses, to reduce vignetting? Especially with IBIS coming now, vignetting could actually become more noticeable. Do we have any idea if the beam splitting from the low pass filter also has an impact on vignetting, and if so, if a new low pass filter like the one from the 1DX III could help?



I think the micro lenses are already their limit, I strongly suspect that that angle is why DPAF only covers 80% of the width and not 100%.


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