CPL Filter: Thin versus 'normal' ?

[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.

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!

[Dirk]

Perhaps do you have anything on this:

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

[Dave Humphries]

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.

[Colin Southern]

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.

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.

[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.

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

[Colin Southern]

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.

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).

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

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!