Old Kodak Wratten Filters

[Shawn Gallagher]

Hi All,

Does anyone know if loose Wratten Filters fade over or shift color over time?

I have some neutral density Wratten Filters that are about 30 years old and was wondering if they are still useable.

Thanks!

 

[Loose Gravel]

In the CRC Handbook of Chemistry and Physics, there is a table with Wratten filter numbers. Each is rated for stability, A, B, C, D for three different types of exposure. The blues, violets, greens, and narrow bands tend to have troubles, where the red end is pretty good.

I don't know if this table is on the web or not.

 

[RalphLambrecht]

Shawn

Use a lightmeter and measure with and without the filter. That should tell you.

 

[DBP]

The worst ones I have seen over the years have been skylights and polarizers. In my experiences, when the wratten filters fail they fade from the edges in, so it is really easy to detect.