Re: Realist notch, 3D CD, and Kodalux

[P3D Paul Talbot <ptww@xxxxxxxxx>]

Gregory J. Wageman observed regarding witness marks:

> oftentimes, the witness mark falls EXACTLY on a perforation

Hmmm.  I'm not an expert in camera mechanics, but I *think* that
in a camera with properly operating, locking, sprocket-hole-fed
film advance, the witness mark should appear in the same spot
every time.  The only variation (as best I can logic-through in
my strictly non-mechanical brain) should be due to film advance
slippage.  If your film is slipping enough to move the witness
mark from squarely between two sprocket holes to "EXACTLY on a
perforation," perhaps you should seriously consider getting it
serviced before you have to post a disaster story a la DrT's
recent trip to Greece?  A camera that does not advance the
film via the sprocket holes would be another story.

> Less often,
> but still useless, is when it falls in shadow and can't be seen...

This is a very good point that had not been mentioned during this
discussion.  I only quibble with the "less often" qualifier.  I
have seen this problem fairly frequently, but have never noticed
the witness mark falling on the sprocket hole itself.  Then again,
how would I even that had happened?

> (And this of course assumes a later-model Realist that HAS the witness
> mark, not all do [my early Ilex Realist doesn't].)

Have you confirmed this by looking at the film gate?  If so, you
might want to forward this information to Charles Piper.  His
rather thorough discussion of witness marks mentions only the
old Iloca and the Verascope F40 as lacking witness marks.

Paul Talbot


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