Colour-polarizing filters?

[athbr]

Was browsing through Horenstein's Colour Photography book and found this interesting passage about color-polarizing filters that produce varying intensities of a colour (or sometimes multiple colours) as you turn the filter.

Yet I haven't been able to find any information about these online much less any available to buy.

Anyone know about this?

The passage in question is attached.View attachment 243214

 

[Bud Hamblen]

If you have a birefringent material between polarizers you can get colors depending on the angle. Never heard of this being used in photo filters before.

 

[Jim Jones]

I've seen these many decades ago, and wasn't impressed. At that time, anything that involved two polarizers and a birefringent sheet before multi-coating presented difficulties that may have precluded image quality adequate for advanced photographers. The sample I once owned appeared to be cheaply made. I never tried to photograph with it.

 

[EdSawyer]

I have one, it's a yellow-blue one. I haven't used it much but it is a pretty cool item, some unique results. they are still out there and available last time I checked, not super common but not extinct.

 

[Bob S]

Hoya sold them years ago.