P3D Re: my 2 cents worth on adjusting projectors

[Paul Talbot <ptww@xxxxxxxxx>]

Bob Aldridge wrote:

> major adjustments may be needed where the chips are not at the same
> height [snip] with the projector adjusted so the homologues are level
> - the apertures will not be, will probably ghost, and will certainly
> float.

This is a very significant point that deserves to be emphasized, IMO!!
Just today I was reading Ferwerda's comments that vertical misalignment
cannot be corrected through projection adjustment.  I didn't understand
why and the text did not explain, but Bob's point makes it clear...you
are trading off one artifact of poor alignment for another.

If you believe in projector adjustment to cure alignment errors, please
go back and read the above two paragraphs again!

Regarding the debate about whether adjustment or non-adjustment is
more conducive to attracting and retaining beginners, perhaps a
distinction must be made between beginning stereo observers and
beginning stereo participants.  I empathize with John R.'s concerns
about public "humiliation" of beginners who mount poorly.  However,
from my experience I have concluded that adjustment-free projection
is far more pleasing to observe.  Constant adjustment of the controls
makes an entire projected show a tedious ordeal to view.  When a
poorly mounted slide is projected and leaves a negative impression,
it can be written off as something wrong with that *slide.*  Constant
projector adjustment leads one to write off *projection itself* as
fatally flawed.  Thus, I endorse the sentiment that education is
the answer to poorly mounted slides, not projector adjustment.

Paul Talbot



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