CPL Filter: Thin versus 'normal' ?

Hi
A local guy is offering me his CPL bought in 2007 and only used the summer that year.
It's a B+W 77mm CPL Thin NOT multicoated.

now I asking, what is the THIN ? That is the first time I hear this,
is there any difference or advantage of having a 'thin' CPL versus the 'normal' sized CPL ?
And is it worth buying this one even if it is not multicoated?
I hear B+W is a very good brand, plus for the multicoating criteria, I never saw any difference in the UV filters,
is it different for CPLs?

Thanks!

Perhaps do you have anything on this:

http://community.dcmag.co.uk/forums/thread/821160.aspx

There's a recent thread here somewhere, no time to find now, but the short answer is probably: if you hold it up sideways, how thick is the framework.
Thin ones will be safer on WA lenses as less chance of vignetting.
For a telephoto lens, it won't matter.

Quote:

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Originally Posted by Zephyrize

Hi
A local guy is offering me his CPL bought in 2007 and only used the summer that year.
It's a B+W 77mm CPL Thin NOT multicoated.

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Thin is indeed "thinner" - thus less vignetting with WA lenses. With many brands it also usually means "no front threads", so if your stacking fiters then the CPL will be the last in line.

in addition of the absence of front threads,
I also heard that I won't be able to put the lens cap...
please tell me it's a joke, at least with a reputable brand like BW.

and what about the coating, does it really make that of a difference ?

Quote:

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Originally Posted by Zephyrize

in addition of the absence of front threads,
I also heard that I won't be able to put the lens cap...
please tell me it's a joke, at least with a reputable brand like BW.

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It's the front threads that the caps normally grip :( (although you can get other sorts). Having just said that, personally, I wouldn't be leaving the CP filter on all the time (it'll cost you 2 stops for a start).

Quote:

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and what about the coating, does it really make that of a difference ?

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Multi-coated is standard practice for UVs these days, but I'm not sure what current state-of-the-art is with CPs (I don't think my Heliopans are SH-PMC) (Their equivalent). Why don't you just grab them - see how you go - and if you don't like them, on sell them!