Re: filmscanners: What causes this ... projection

[Arthur Entlich <artistic@ampsc.com>]

Steve Greenbank wrote:

>>> I felt that the test onto the paper would also show
>>> more clearly what the scanner sees.
>> 
>> I am afraid that I do not see the logic of this.  I do not see how the
>> projection of a slide onto smooth paper would simulate a scan; I can see
> 
> the
> 
>> point of comparing the projection onto smooth paper versus the projection
>> onto a projection screen.  I think you may be making a number of
> 
> unwarranted
> 
>> assumptions.
> 
> 
> There may be unwarranted assumptions but it was never meant to be a
> scientific experiment- hence I "felt".
> 
> The reason I suspect the paper is more representative of the scannner is:
> 
> 1)  All screens are made this way and I would have thought it would be
> cheaper to manufacturer it flat. Manufacturers obviously texture the surface
> to improve the image. Whereas the scanner is just reporting what it sees.
> 
> 2) The scanner looks at a flat surface (if you scan the right surface) so I
> just felt that viewing the output on a flat surface would be more
> representative.
> 
> Steve


Most slide screens use a textures surface for one or more of several 
reasons.  Either to even out or intensify the light reflected back to 
the viewer.  The older glass bead or newer lenticular screens both use 
systems to reflect back more light to the center viewers, and improve 
contrast in rooms that are not fully dark.  The cheaper basic screens 
which simply use a textured surface do so to prevent uneven reflection 
and to better hide sags, creases, scuffs and damages in the screen surface.


I would agree that a quality piece of flat heavyweight 98 white paper or 
card stock would remove many of the artifacts most projector screens add 
in an attempt to "improve" (for larger viewing in a semi dark room) 
image quality.

Art