Has anyone noticed a colour shift when using their CPL? I've noticed some shots where I've used a CPL and some areas exhibited a slight purplish/blue cast. I can't post the picture for copyright reasons and I haven't really been able to recreate the conditions.
It's basically a wide shot of a condo apartment with the sun high right, out of frame. CPL was set to cut glare from water surface in the swimming pool and also to deepen the blue skies. Buildings were a pale yellow. The resulting pictures yielded a very nicely saturated blue swimming pool and skies but my buildings ended up looking a little purplish and it was a pain trying to colour correct in post.
Can someone point me in the right direction? What have I done wrong and what can I do when using a CPL to avoid a similar problem?