Film-Tech Forum ARCHIVE: Master Image Filter Wheel question

This is topic Master Image Filter Wheel question in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Jim Cassedy (Member # 4115) on 05-08-2015, 02:15 PM:

Are the polarizing filters of a Master Imgage 3D system sandwiched inside the spinning
glass disk, or are they applied to one of the exterior surfaces?

(In other words- - what I'm trying to find out is how "protected" the actual
filter material is from damage when cleaning the disk, etc)

Tnx!

Posted by Kris Verhanneman (Member # 5562) on 05-08-2015, 02:30 PM:

Hello, the filter is on the outside of the disk. You can scratch it. (talking about the rotating disk version not the horizon version).

Posted by Stephan Shelley (Member # 8587) on 05-08-2015, 08:21 PM:

The disk is plastic and as such both sides can scratch.

Posted by Marcel Birgelen (Member # 6801) on 05-09-2015, 11:43 PM:

The disc indeed seems to be some sort of plexiglass. I have never given it much thought, but isn't the disc far to thick for just a linear polarizer and retarder? Sure, you need a certain thickness to ensure stability, so wouldn't it actually make some sense to put those layers inside the disc, sandwiched between a protective layer of clear plexiglass?

Posted by Stephan Shelley (Member # 8587) on 05-13-2015, 05:57 PM:

Not sure if they are sandwiched or just laminated to one side the polarizing material.The main body is polycarbonate. Much stronger than acrylic.It does spin at a very high speed.

Posted by Justin Hamaker (Member # 2165) on 05-13-2015, 06:41 PM:

The disc is definitely plexiglass. The 'wedges' are some sort of plastic or vinyl which are adhered to the disc. Not sure if they are laminated or just an adhesive, but they can be pealed off is you're not careful.

Posted by Phil Ranucci (Member # 3820) on 05-13-2015, 10:46 PM:

When cleaning don't spray the disc, spray the microfiber cloth. If the filter gets wet it will peel off and make a racket when it gets up to speed.