Film-Tech Forum ARCHIVE: Anamorphic lens in digital scope?

This is topic Anamorphic lens in digital scope? in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Frank Angel (Member # 248) on 03-30-2012, 12:59 PM:

Some of my friends on the Drive-In group asked about how digital deals with scope. Their concern, of course, is always getting every lumen of light out of the system for those huge, zero gain screens.

I have done a search here because I thought I read quite awhile back that scope in DCinema CAN be done using an anamorphic lens as is done with film scope thus not loosing top and bottom light since the whole chip will be used instead of letterboxing on the chip and zooming. I know in non-DCI systems projection scope can be done either way. Some even have motorized jigs that can move the anamporhic lens in front of the prime. Can this, or should I say IS this done today in DCinema?

Posted by Steve Guttag (Member # 268) on 03-30-2012, 01:32 PM:

Wrong forum...the short answer is YES. Anamorphics can be used in DCI systems and they are "REQUIRED" to be motorized for "unattended lens changes."

At present, Christie, NEC and Sony (at least they list it) offer them in the US. Kinoton, I now offers them as well.

Using an anamorphic will yield about 23% more light in Scope. They will help balance the light between scope and flat so that the lamp lasts longer too.

-Steve

Posted by Frank Cox (Member # 6258) on 03-30-2012, 02:39 PM:

I have one on my Christie projector. My screen size is apparently such that a standard zoom lens alone wouldn't work. The tech who installed it told me that it was the first time he had installed an auxiliary lens.

The scope cue automatically drives the lens over into place.

Posted by Frank Angel (Member # 248) on 03-31-2012, 04:39 PM:

Thank you, guys, and thanks for moving this post.

Also, what is the actual physical AR of the DLP chip? Is it 16:9, 4:3?

Posted by Carsten Kurz (Member # 5396) on 03-31-2012, 04:55 PM:

Flat=1.85:1

To be more precise, the native full pixel raster is 1.89:1 (2048*1080).

For flat features, it is used to 1998*1080, for 'normal' scope, 2048*858.

Double each dimension for 4k.

With an anamorphic lens, the 2048*858 scope image is stretched vertically to 2048*1080 in realtime by the ICP in the projector.

- Carsten