T3D TECH-3D digest 559

[David Stone <106213.131@xxxxxxxxxxxxxx>]

Colour Anaglyphs

I am grateful for Dr Carter's explanation of how colour anaglyphs work. 
However, after replacing the gel cyan filter, all of which have a degree of
spill over into the red, with the closest dichroic filter to complement the
red filter, which had a quite sharp cut off, the same problem of
satisfactory colour reproduction still remained.  Perhaps this was due to
an acknowledged imperfection of complementary match or because of the off
axis wavelenth shift of the dichroic.   If anyone has had success with a
complementry pair of dichroics it would be valuable to hear of it and,
indeed, the source of the filters.

Panoramic Colour Anaglyphs

Also I am indebted to Boris for the twin rig gen.  My interest in colour
anaglyphs originally stemed not from panoramas but because I want to make
more  use of a digital projector for viewing standard field stereo on a 6 X
4 foot screen.

Eddie Butt (Stereoscopic Journal No141, July 1998) has modified cameras by
adding a box on the front with a direct entry, to the image plane, via a
red filter and an offset entry through a cyan filter with the aid of
mirrors.    This is not an original idea of his, at least one patent exists
covering every conceivable mirror configuration.  My own intended approach
to the panoramic case is to modify a Nimslo camera by milling out the
septums, in order to get a 72X24mm image plane format, and use a medium
format lens. This idea was suggested by Andrew Davidhazy. The rest of my
approach amounts to taking sequentially on the same piece of 35mm film with
the aid of a slide bar with filters attached to cover at the appropriate
points on its track.


David