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I am looking for a polarizer gel for our lights, but specifically one for creating left or right handed circular polarization.

I can find linear gels all over the place. I can even find circular filters for the camera. But no circular gels.

Does this even exist or is it something that isn't possible to do in a gel?

Edit since there are so many questions and links to other questions:

Quick high level explanation for what I am attempting to experiment with:

On set I will have multiple light sources. I want one set to be Right-handed and the other will be Left-handed.

Then 2 cameras will shoot the same scene, one with a Right-handed filter and the other with a Left-handed filter.

Why circular and not linear? If you are using linear polarized light and linear polarized filters then your filter has to be correctly aligned to properly work. Rotating the filter will change what polarization it filters out. Also, linear polarization can change it's direction easily when bouncing off different surfaces.

Think of a 3D movie that uses this tech. 2 projectors use left and right handed polarization. Your glasses filter out each one almost perfectly AND you can tilt your head without screwing with what light is being filtered through.

I'm not an expert on this topic but I do believe I know enough to know what I need. I found in another thread that in photography terminology on this topic is a bit "messed up" and may have different meanings to different people.

Michael C
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Sean256
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    Why would you need a circular polarizer for gelling lights? – Michael C Dec 21 '15 at 22:49
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    This question doesn't really make sense. I would start here: What is the difference between a linear and a circular polarizer? – dpollitt Dec 21 '15 at 22:51
  • If you find an existing question for which you desire a more complete answer, the proper way to address that here is by offering a bounty on the existing question, rather than asking the same question again. – Michael C Dec 21 '15 at 22:53
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    @MichaelClark correct, but that other question has an answer that was marked as correct but did not answer it fully. I had commented on it and you yourself replied acknowledging it. – Sean256 Dec 21 '15 at 23:10
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    I strongly believe this question deserves a good answer. @dpollitt, the top answer for the question you linked to states, "...there are no cases when you would want a linear polarizer instead of a circular one." – Octopus Dec 21 '15 at 23:14
  • @Sean256 Then rather than post a duplicate question here you can post a better answer to the other question or offer a bounty to see if someone else can. – Michael C Dec 21 '15 at 23:44
  • Michael Clark, there is a difference of terms when it comes to "circular polarization". I think OP is looking for something that creates a circularly polarized light-wave. NOT a linear-filter placed in front of a camera lens that photographers call a "circular polarizer". An example is on a 3D movie, where circularly polarized light is used to filter out light from each eye non-withstanding changes in angle. An example of such a filter (not a gel):

    http://www.edmundoptics.com/optics/polarizers/circular-polarizers/circular-polarizers/3624/

     – Daymon Schroeder Dec 21 '15 at 23:54
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    @DaymonSchroeder Then the question needs to be modified to reflect the unique use case (now done by the O.P.) rather than just ask the same question and complain that "it is not really the same question." Likewise, we don't ask repeat questions if we find less than satisfactory answers where the same question was previously asked. Rather, we correct the problems with the original question/answers. – Michael C Dec 22 '15 at 00:04
  • With the edits to the question, it is no longer a duplicate of the question marked. – Michael C Mar 23 '19 at 06:08
  • TL;DR: For cross polarized lighting purposes, you always want linear polarizers on anything but the camera, no matter how circular your camera filter is. – rackandboneman May 13 '19 at 09:34

2 Answers2

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What you seem to be looking for does not seem to exist in gel form. The type of filter you require for what you wish to do is available from Edmund Optics. They offer these filters with either a rigid plastic or flexible film substrate in both right and left hand versions. The filters with the film substrate option, while not gels, can be cut and flexed similarly to a gel filter.

Michael C
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The polarizer used by the digital camera community is actually a standard linear sandwiched to a second filter called a retarder. The first filter does the trick; it limits transmission to light waves that oscillate in a plane aligned with the plane of polarization of the filter. The second filter scrambles the orientation of the light waves. The result is, the camera sees the rays as if they were not polarized. The reason is, modern digital cameras often utilize polarization for auto-focus and exposure determination. A linear polarizer might compromise the camera’s automation.

Alan Marcus
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