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[pv17vv]

Hello all !

Just purchased a handfull of Series Kodak filters.

What is exactly the difference between yellow K2 and yellow CK3 ?

Why should still- and movie-cameras need different filters ?

Thanks.

Georges

[C. Henry]

Georges;

My copy of the Photo Lab Index says that "K2" is an old designation for a #8 filter and "K3" for a #9 filter. A #9 is a deeper yellow than a #8. The PLI also indicates that a #9 will usually over correct cloud - clear sky contrast in black & white photography.
As for the "CK3" designation, I'm guessing that it was just a marketing ploy to try to convince amateur movie people that they need special filters instead of the more generally used ones.

C. Henry

[Les]

Well there's this scan of a kodak catalog that admits the CK3 is a cine filter, but it doesn't say why. the difference (at least in Kodak's graph) between a K2 and K3 (#8 and #9) is minimal,

But maybe movie film stock was slightly different than 35mm? and needed the sight difference between a K2 and K3? If so, why the Cine? why not just say K3 for movies?

A Marketing gimmick?

http://kodak.3106.net/index.php?p=303&cam=919
_________________
"In order to invent, you need a good imagination and a lot of junk" Thomas Edison

[glennfromwy]

CK = cine Kodak. Why? I know nothing.
_________________
Glenn

"Wyoming - Where everybody is somebody else's weirdo"

[pv17vv]

Thanks my Friends.

Observation of said filter after a good cleaning shows two things :

1 it is a very small bit denser than K2

2 it is half thinner in the mount, as if one of both glasses was missing

K3 in plain glass instead of dyes between cemented glass ?

[glennfromwy]

That's very possible. Regular Wratten filters, such as the K-2 are gelatin between two glasses.
The CK-3 is probably dyed glass. It probably has a different spectral sensitivity, too. I'm going to speculate that it is a pro item.
_________________
Glenn

"Wyoming - Where everybody is somebody else's weirdo"