[opendtv] Re: Red camera lenses

  • From: Mark Schubin <tvmark@xxxxxxxxxxxxx>
  • To: opendtv@xxxxxxxxxxxxx
  • Date: Sun, 03 Jun 2007 22:24:29 -0400

Manfredi, Albert E wrote:

Mark Schubin wrote:

It is also possible to change the color-separation system. There
have been three techniques for this: rotating color filters
(used in the old CBS-color system, the Colorgraphics system, and
the Apollo mission camera), stacked sensors allowing
higher-energy colors to pass through the layers intended for
lower-energy colors (the Foveon sensor used in Sigma cameras),
and on-chip color filtering -- stripes (Abtography, the
Panavision Genesis, old inexpensive color video cameras) or on a
pixel basis (Bayer, diagonal, or the lower-ratio systems used in
some of Sony's Clear-Vid systems). The color filters are most
popular: stripes in the Panavision Genesis and Bayer in the ARRI
D20, the Dalsa Evolution and Origin, the EasyLook Modula HD, the
NAC Memrecam fx K4, the Red One, the Silicon Optics SI-2K, SI-2K
Mini, and SI-1920, the Vision Research Phantom HD and Phantom 65,
the Weinberger Cine Speedcam, the Weisscam HS-1, and many
smaller-format cameras as well as cameras not intended for TV
use.


Is color filtering on an individual pixel basis, the last option you
describe, what is used by digital still cameras?

Yes.


I believe it is, and
would seem to be the most compatible way to make use of 35mm/APS lenses
for video.
From a fixed-focal-length image-quality standpoint, perhaps, but that's a tiny fraction of what a video lens must do. It needs to maintain focus, for example, over its entire zoom range (which, today, even in smallish lenses, tends to be around 20:1 and can go as high as 101:1 before the use of built-in extenders). 

TTFN,
Mark





----------------------------------------------------------------------
You can UNSUBSCRIBE from the OpenDTV list in two ways:
- Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org 
- By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word 
unsubscribe in the subject line.

Other related posts:

  1. Home
  2. opendtv
  3. Archive
  4. 06-2007