My CP is too stiff - won't turn

My B+W F-Pro 77mm CP has decided to stiffen up and quit turning. It will turn a bit, then is so stiff that it starts to come off the lens when I turn it. Is there anything I can do to loosen it up?

Nobody? Has this never happened to anyone else? Am I crazy? Is is not suposed to turn, but was too loose when I got it and now is working correctly? I thought Circular Polarizers were supposed to turn freely. Mine only turns about an 1/8th of a turn, and then doesn't want to turn anymore...

No, they're supposed to spin freely. Check around the edge to see if it's gotten dented or if something's caught in the gap between the two rings.

mine's came like that out of the box. brand new B+W. i didnt find out until a month after when i opened it up to use.

My B&W Kasemann CP's all spin with very little effort.

If you lay it down on a very flat surface with a light behind it, do you see any gaps between surface and filter?

maybe it needs some breaking in? But it seems odd that it is stiff out of the box. Where did you buy it from?

Jon wrote in post #10396224
No, they're supposed to spin freely. Check around the edge to see if it's gotten dented or if something's caught in the gap between the two rings.

Thanks, Jon - I'll take a closer look.

keitaro wrote in post #10400902
maybe it needs some breaking in? But it seems odd that it is stiff out of the box. Where did you buy it from?

Mine was fine out of the box and then stiffened up later - someone else had one that was stiff out of the box. I got mine from maxsaver...

Kasrielle wrote in post #10401082
stiff out of the box

hmm...usually they're stiff going into the box, but not on the way out...we're talking about filters here, right?

i'd grab a flashlight and gaze into the gap between rings and look for grit or any visible warping/bends/dents...​your post from yesterday said it was initially "too loose" and you were wondering if it is now working properly, which makes me think it was turning freely right out of the box but something got in there and is stopping it from turning now...

wintermutant wrote in post #10402737
hmm...usually they're stiff going into the box, but not on the way out...we're talking about filters here, right?

i'd grab a flashlight and gaze into the gap between rings and look for grit or any visible warping/bends/dents...​your post from yesterday said it was initially "too loose" and you were wondering if it is now working properly, which makes me think it was turning freely right out of the box but something got in there and is stopping it from turning now...

I've taken a really close look and can't see anything obvious - near as I can tell it seems to have gotten a fraction misthreaded. It seems to be sticking on one side. That being said - I put it on a lens and it turns a bit easier than when it's just in my hands. I remember being stupid one day and putting it on over my UV filter, and then they didn't want to come apart - it took forever to get them back apart. I think it became misthreaded then. I'll never do that again!

In any case - it's usuable.