CPL maximum thickness on 16-35 USM II

[canonuser78]

Hi there,

I am about to buy a 16-35mm USM II Lens for the 6D body and I wanted to know what is the maximum recommended CPL filter thickness in order to avoid the vignetting .7mm can be to thick ?

Thanks,

[hsbn · Accepted solution]

You meant 7mm? I use the low profile CPL that is 5mm thick and it works fine with the 16-35. But you don't want to use it on the sky due to un-even polarization effect with Wide angle lens. I recommend the 5mm frame.

[canonuser78]

Thanks,

I have read about uneven polarization effect on wide angle lenses -  what is the solution in this case ? we use the CPL filter to make the sky less brighter right ? how can we avoid this unwanted side effect , using ND filters instead of CPL ?

[hsbn]

Normally I will try to avoid using it with the sky. However in some case, I need to cut reflection so I use it but I only turn it slightly so that the effect would be minimal (you can see this through the view finder). If the sky is not that much brighter than your foreground, you can pull the sky down in post processing. In case that I need heavy polarization effect, I'll take 2 photos and merge them in post. It is a problem only if it is a cloudless blue sky. With a lot of cloud, it's not a problem.

[canonuser78]

many thanks,