Re: [photo-3d] Re: TDC Vivid reflection problem

["John A. Rupkalvis" <stereoscope@xxxxxxxxxxxxx>]

----- Original Message -----
From: <cfholzner@xxxxxxxx>
To: <photo-3d@xxxxxxxxxxxxxxx>
Sent: Thursday, February 15, 2001 4:39 PM
Subject: [photo-3d] Re: TDC Vivid reflection problem


> > > number of TDC Vivid owners reported the same
> > > problem.  Paul Talbot mentioned that Don Lopp (sp?)
> > > had found a fix for it> >
> > > Any help to resolve this issue will be appreciated!
> > I call it Springsteen's Comet.  In situations where bright light is
> reflected up from the
> > ground, there is a molded shape in the TDC Vivid's left
> > compartment, at the top, that reflects light off its curved edge
> > and creates a milky white spectre, shaped a bit like a comet,
> > centered near the bottom of the left image.  It can be extremely
> > subtle or quite severe, depending on conditions.  Often it does not
> > occur at all.  I've seen it in images from Vivids other than my own
> > - the offending surface is part of the camera design and is in all
> > Vivids.  It's not a leak.
> > I've long intended to paint or otherwise dull the reflecting edge.
> > Never got around to it.  Paul Talbot when visiting here even devised
> > a pattern for a little conical baffle to cut from flocked paper and
> > insert into the left chamber.
>
> Has anyone actually fixed a Vivid with this problem?
>
> Mine has the comet too.  Since the little molded shape of metal is
> already a dull black, painting it with flat black paint doesn't make
> it look any darker to me and there are other black surfaces in there
> that reflect light too.  If someone has a "for sure" fix I would like
> to know before I spend another roll of film.
>
> Thanks,
>
> Chuck

I don't know about the Vivid, but I would guess that it might be similar to
a reflection problem in the Busch Verascope F40.  In that camera, the
chamber sides are perpendicular to the film plane.  As a result, bright
lights near the edge of the frame reflected back into the frame, causing a
streak similar in appearance to a light flare (which it wasn't).  For this
camera, the fix was to machine these walls back at an angle, so that the
light reflected back toward the front, away from the film.  Remember, the
angle of incidence equals the angle of reflectance.

JR