P3D Re: my 2 cents worth on adjusting projectors

[Paul Talbot <ptww@xxxxxxxxx>]

Bob Aldridge wrote:

> The classic example where projector adjustment would be needed is
> where a complete slide mount does not sit level in the projector gate.
> Here, adjusting the vertical will not only level the homologues in the
> scene, but also level the frames... And this, of course, is why one
> has to make gentle vertical adjustments in mixed author shows.

Thanks for another perfectly clear explanation!  To be more precise,
however, perhaps the last line should read "mixed mount*" shows
rather than "mixed author" shows.  I do have to wonder, though,
about how significantly different mounts are in their "levelness."

> If the authors of these slides took their own slides and put them
> into their own AV show, they would probably do a bit of "shimming"
> (sticking tape to the top of the slide, so when it's dropped upside
> down into the projector it lands level). Unfortunately, if you project
> with a different type of projector, the shims may be in the wrong
> place, so the slide does not land level. Hence the need for gentle
> virtical adjustment.

Sounds reasonable.  But to what extent is the need for this shimming
due to the mount, vs the projector?

And somehow I don't get the impression that many of the comments on
this topic have been addressing concerns caused by shimming.  The
focus seems to have been mainly on the appropriateness of using
projector adjustment to offset beginners' errors.

Thanks for the calm, reasoned input into this emotionally-charged
discussion, Bob!

* note, however, a shimmed mount would have to be considered as
different from an un-shimmed but otherwise identical mount.

Paul Talbot


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