Film-Tech Forum ARCHIVE: Technicolor 3D lenses, ATTN: Mark Gulbrandsen

This is topic Technicolor 3D lenses, ATTN: Mark Gulbrandsen in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Craig Call (Member # 2845) on 03-29-2014, 08:59 PM:

Schneider Technicolor came out with these stunning 3D lenses (albeit expensive). So what is the difference between the "Tpye K-Stereo MC", the "Type C-Stereo MC" and the "Type G-Stereo MC"? I figured they were just different FOCAL LENGTHS but Technicolor doesn't indicate that. I am currently using the Technicolor Type K-Stereo MC, but it only gives me a 4 ft. picture. I have the Technicolor 3D Magnacom (go figure) which enlarges this picture to 11 ft. x 4.5 ft. I am trying to fill a 17 ft. x 8 ft. screen. I hope you find this, Mark. You seem to be the man to ask. You worked on my screening rooms when I lived in Utah. I wish you were here in L.A.!! My lens (Type K) is like new, but if there is a different type that will "nearly" fill my screen size I would be much happier. I can also get the "Type S" and "Type T", but these seem to be attachments that I'm guessing will slightly alter the focal length. 'Hope to hear from you soon.

Posted by Mark Gulbrandsen (Member # 72) on 04-01-2014, 10:36 PM:

Hi. Craig,

Yes, they are different focal lengths. Technicolor never really let on to what the focal lengths were during the training class. But those lenses in combination with the proper magnifier or reducer allows them to accommodate just about any throw distance - screen size out there. I don't think it would be too difficult to measure the focal length of the primary lenses.
The other interesting thing about those lenses are the polarizers. At training class they said that they were the most important part of the system and a brand new polarizer design. You have to have both the front and the rear polarizers in place for the system to work. Initially I thought the rear was just a heat filter but it's both a heat filter and partial polarizer. There has to be a patent on file for this system some place!
P.S., I have a feeling the 3-D lenses are nothing more than matched pairs and modified Cinelux Ultra lenses. There are still a lot of these lenses laying around in theaters out there. Most were never recalled.

Posted by Don Furr (Member # 1469) on 04-02-2014, 03:00 PM:

Mark it would seem to me that with "dual" polarizers it would eat up even more light than the Sirius 3D lenses! Not a good thing.

Posted by Mark Gulbrandsen (Member # 72) on 04-04-2014, 08:43 AM:

Not necessarily Don. Polarizer filters are made in many different densities or amounts of transmissivity. the combination of the two filters on those lenses doesn't add up to anything worse than 50% light loss like most other systems.

Posted by Don Furr (Member # 1469) on 04-04-2014, 06:05 PM:

That's good to know..
Thanks Mark.