# B+W 82mm Kaesemann Circular Polarizer with Multi-Resistant Coating question



## DaveMiko (Apr 8, 2014)

Does anyone know if this filter: B+W 82mm Kaesemann Circular Polarizer with Multi-Resistant Coating
produces vignetting using the Canon 16-35mm and/or the Canon 24-70mm lenses on the Canon 1DX and/or the Canon 5D Mark III?

Also, I understand that one thing that's pretty hard to miss is that it polarizes the sky unevenly. Is this too conspicuous that IQ is compromised?!


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## sagittariansrock (Apr 8, 2014)

Not with 5DIII (and 1D X, I am sure) with the 24-70.


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## neuroanatomist (Apr 8, 2014)

Even their thickest CPL, the standard F-Pro Mount, is fine on the 24-70 II. In a quick and dirty test, I can stack an F-Pro UV (5mm) on an XS-Pro UV (3.4mm) on my 24-70 II with no additional vignetting. So, the F-Pro CPL (7mm) should be fine. 

I tested the 16-35 II a bit more thoroughly:





Based on those results, you might get a little more optical vignetting (but not mechanical vignetting) with a standard CPL. The Slim CPL (5 mm, no front threads) or the XS-Pro CPL (4 mm, with front threads) would be fine.


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## DaveMiko (Apr 8, 2014)

sagittariansrock said:


> Not with 5DIII (and 1D X, I am sure) with the 24-70.





neuroanatomist said:


> Even their thickest CPL, the standard F-Pro Mount, is fine on the 24-70 II. In a quick and dirty test, I can stack an F-Pro UV (5mm) on an XS-Pro UV (3.4mm) on my 24-70 II with no additional vignetting. So, the F-Pro CPL (7mm) should be fine.
> 
> I tested the 16-35 II a bit more thoroughly:
> 
> ...



Thanks guys for your help. ... Neuro's detailed evidence, in particular, cleared up my confusion.


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## PhotographerJim (Apr 8, 2014)

DaveMiko said:


> Also, I understand that one thing that's pretty hard to miss is that it polarizes the sky unevenly. Is this too conspicuous that IQ is compromised?!



Most wide-angle lenses w/circular polarizer will do this, if I understand right. See: http://havecamerawilltravel.com/photographer/polarizing-filter-wideangle-lens
Has to do with physics and the angle of the sun vs. camera.


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## mackguyver (Apr 8, 2014)

PhotographerJim said:


> DaveMiko said:
> 
> 
> > Also, I understand that one thing that's pretty hard to miss is that it polarizes the sky unevenly. Is this too conspicuous that IQ is compromised?!
> ...


According to B+W, the phenomenon begins under 28mm (or equivalent) focal lengths, but it's all about how you use it and whether or not you are okay with it. The sky has a natural gradient at or under the focal length anyways, so putting the dark part at the top of the frame, as long as it's level, usually works.


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## DaveMiko (Apr 8, 2014)

I took some test shots for this filter (standard F-Pro mount) with my 24-70 mounted on my 1DX and, I've got to say, at the 24 mm wide end I noticed no vignetting or uneven polarisation of the sky.


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## yorgasor (Apr 9, 2014)

I've heard the same thing about polarizers on wide angle lenses, but either the B&W thin pro filter doesn't have this issue, or maybe the time of day was just right: 

I took a bunch of photos on this bright, clear day with my Zeiss 21mm f/2.8 and didn't have a problem with any of them. I even took this panorama shot with it (2 photos) and it came out fine.


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## sagittariansrock (Apr 9, 2014)

DaveMiko said:


> I took some test shots for this filter (standard F-Pro mount) with my 24-70 mounted on my 1DX and, I've got to say, at the 24 mm wide end I noticed no vignetting or uneven polarisation of the sky.



It is an entirely unscientific and subjective observation, but I have rarely noticed uneven polarization above 24mm-equivalent FLs (~15mm on APS-C).


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## DaveMiko (Apr 9, 2014)

sagittariansrock said:


> DaveMiko said:
> 
> 
> > I took some test shots for this filter (standard F-Pro mount) with my 24-70 mounted on my 1DX and, I've got to say, at the 24 mm wide end I noticed no vignetting or uneven polarisation of the sky.
> ...



I had no pretence of scientific accuracy and/or strictly observing the criteria of the scientific method in my little test.


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## DaveMiko (Apr 9, 2014)

PhotographerJim said:


> DaveMiko said:
> 
> 
> > Also, I understand that one thing that's pretty hard to miss is that it polarizes the sky unevenly. Is this too conspicuous that IQ is compromised?!
> ...



Thanks. 8)


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## sagittariansrock (Apr 9, 2014)

DaveMiko said:


> sagittariansrock said:
> 
> 
> > DaveMiko said:
> ...



Lol, I was pointing at my own observation (unscientific and subjective), because I'm sure it is possible to get uneven polarization at longer FLs under certain conditions.


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## DaveMiko (Apr 9, 2014)

sagittariansrock said:


> DaveMiko said:
> 
> 
> > sagittariansrock said:
> ...


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## SoullessPolack (Apr 10, 2014)

yorgasor said:


> I've heard the same thing about polarizers on wide angle lenses, but either the B&W thin pro filter doesn't have this issue, or maybe the time of day was just right:
> 
> I took a bunch of photos on this bright, clear day with my Zeiss 21mm f/2.8 and didn't have a problem with any of them. I even took this panorama shot with it (2 photos) and it came out fine.



The sun is roughly behind you in this image, which is why you see little/no uneven polarization. Had you turn 90° to the left or to the right, you would notice the unevenness more.


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## sagittariansrock (Apr 10, 2014)

SoullessPolack said:


> yorgasor said:
> 
> 
> > I've heard the same thing about polarizers on wide angle lenses, but either the B&W thin pro filter doesn't have this issue, or maybe the time of day was just right:
> ...



I'd rather guess the sun is high up and around 4 or 5 o'clock position. I think there is uneven-ness in the sky, except there isn't a clear, continuous stretch for that to be apparent. My 2c.


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