Restoration - Doctor Who: Theta-G                          beeblebroxcompany.org

Color Correction

* Registration: There's an FCP filter to offset the color channels to shift the
  VHS color back into place.

The Newvicon Tube

Theta-G was shot in part with a single-tube Newvicon camera, which was one of
the last consumer cameras to be built with an imaging tube before the advent 
of light-sensitive chips and VTR/camera combinations called "camcorders."

Newvicon was the trade name for a special type of saticon tube that operated
better in low-light situations.

Single tube cameras derive red, green and blue from their single image using
a striped color filter that pulls each color from every third line of the
video. This does mean that the color signal is two-thirds less detailed than
the BW picture it's laid upon, but the compromise has been perfectly acceptible
to consumers of single tube/chip cameras.

The Damage

Long before production, the tube (or the color filter) developed a malfunction
that appeared to kill the blue component of the signal. Shots in plain white
rooms became a preppy battle between pink and green, despite attempts to white
balance the image.

Below are two examples, with a third image from a different camera provided as
reference.

Natural light, afternoon, overcast


Indoor fluorescent


Reference: natural light, late afternoon, haze


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Restoration - Doctor Who: Theta-G                          beeblebroxcompany.org