Xref: utzoo comp.graphics:17061 rec.video:19441
Newsgroups: comp.graphics,rec.video
Path: utzoo!utgpu!news-server.csri.toronto.edu!torsqnt!geac!alias!gsutiono
From: gsutiono@alias.com (Guno Sutiono)
Subject: Questions on video camera
Message-ID: <1991Apr4.200358.2223@alias.com>
Keywords: camera, field of view, video
Sender: news@alias.com (USENET News)
Organization: Alias Research, Inc. Toronto ON Canada
Date: Thu, 4 Apr 91 20:03:58 GMT

We are looking for some information regarding the geometry of video camcorder 
optics, specifically field of view determination from physical camera settings.

Any help would be appreciated...

Q1. Is there a standard for CCD size specification in a video camera ?
    For instance, if my video camera has a 1/2" CCD, does this imply that
    there are specific dimensions for CCD size? If so, what are they ? In
    what standard dimensions are CCD's commonly available?
 
Q2. Based on the pinhole camera model, the field of view (FOV) can be
    determined by the film size (e.g. 35mm film) and the associated lens'
    focal length (e.g. 50mm) by using the equation: 
               FOV = 2 * arctan( 0.5 * film size / focal length )
    When will this pinhole camera break down in reality ?

Q3. In the case of video camera, can we just substitute the "film size" 
      variable in the previous equation with the "CCD sensor size" ?

Q4. The commercial CamCorders that are available nowadays use
      terminology such as 6X, 8X, or 10X to specify the power of the zoom 
      factor they support.  Is there an industrial standard method for 
      mapping these zoom factors to range of focal length ?
      e.g. It seems that 8X implies an 8.5~68mm lens and 10X implies an
      8~80mm lens in a 1/2" CCD video camcorder.

Q5. Is the image captured from a video camera appearing on a TV
      monitor a cropped representation of what is on the CCD (specifically,
      is it possible for the optical centre of the image on a TV monitor 
      to be offset in image space from the optical centre of the image
      falling on the CCD) ?  If so, how can we determine the offset ?
      Are there any other transformations which are applied to the image
      falling on the CCD during its conversion to a video signal?

Q6. Can we generalize the above approach for obtaining field of view to a
     movie camera ?