# B+W 77mm XS-Pro Kaesemann High Transmission CP vignetting w 70-200



## Vern (Oct 28, 2016)

I purchased the title CP to use on a hiking trip to Switzerland earlier this month and noticed intermittent vignetting as seen in the attached image when used with the 70-200 2.8II. I started removing the hood (just in case that was contributing) after noticing this, but still saw the affect - but only in some shots. This one is at 90 mm and f8, but a later shot at (second one below) at 75 mm and f11 is free from this. I'm surprised that a thin filter would do this and that relatively small changes in focal length and f-stop would make it come and go. (screenshots of exifs attached too for reference)

Am I missing something obvious in how to avoid this? I'm willing to get a different CP if that's the problem.

The corresponding 82 mm version never showed this on the 24-70 II or the 24 TS.


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## Vern (Oct 28, 2016)

forgot to mention that these are JPEGs processed from RAW files after using Canon's DLO and peripheral illumination function in DPP4.


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## neuroanatomist (Oct 28, 2016)

IMO, it's a consequence of the 70-200/2.8L IS II design. Consider that the MkI versions of the 'zoom trinity' – the 16-35/2.8 and 24-70/2.8 – had 77mm filters like the original 70-200/2.8 IS, but the ultrawide and standard zooms moved to an 82mm filter for the MkII versions, whereas the telezoom remained at 77mm. I think that optical design cuts a little to close to the edge.

FWIW, this has come up before with UV filters, where the standard F-Pro mount adds vignetting – it's the only lens I've seen where that occurs. 

http://www.canonrumors.com/forum/index.php?topic=5296.msg104929#msg104929

You can use PS to correct the vignetting beyond the default lens profile, if you prefer.


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## Vern (Oct 28, 2016)

neuroanatomist said:


> IMO, it's a consequence of the 70-200/2.8L IS II design. Consider that the MkI versions of the 'zoom trinity' – the 16-35/2.8 and 24-70/2.8 – had 77mm filters like the original 70-200/2.8 IS, but the ultrawide and standard zooms moved to an 82mm filter for the MkII versions, whereas the telezoom remained at 77mm. I think that optical design cuts a little to close to the edge.
> 
> FWIW, this has come up before with UV filters, where the standard F-Pro mount adds vignetting – it's the only lens I've seen where that occurs.
> 
> ...



Thanks neuro - makes sense and I do recall seeing this occasionally with the prior CP I used with the lens. I will take these into PS and fix the issue when needed.


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