non-linear horizontal distortion in anamorphic DVD

Recently, I have acquired a DVD movie "Mamma Roma" by P.P.Pasolini
issued by Criterion, which is famous for its high-quality digital
remastering of old movie classics. The disk is anamorphic 16:9, and the
image fills the screen of my 16:9 LCD display (BENQ, 32") in the
Full-screen or Anamorphic mode, supposedly undistorted. To my great
disappointment, when the movie gets to slow horizontal panning takes of
a static landscape (there are quite a few of them in the film), I see
gradual distortion of the objects in the frame as they cross the screen
from, say, the right margin to the center and then to the left margin.
This effect is very disturbing to eyes. To assess it quantitatively, I
made the movement pause several times and measured with a ruler the
width of a certain object in different positions on the screen. It
turns out that, compared to their width in the center, the objects are
by 35-40% (!!!) wider near the side edges of the screen. The effect is
the same whether I watch it through a PC (with PowerDVD software) or
through a stand-alone DVD player. However, when I set the display to a
4:3 mode and keep the original aspect ratio of 16:9 (with black bars on
all four sides of the display) the object widening is much smaller
(about 10%), and the eye practically does not discern it. It is clear
that a part of the fault lies in the disk information itself, but a
greater part pertains to other components (decoding software and
hardware? properties of the display?). I should greatly appreciate a
professional explanation. Are there ways to solve this problem? I
should note that I have run a number of other anamorphic disks and
haven't felt this phenomenon, but now I realise that this is because
most of panning scenes are accomponied by movements of dynamic objects
(people, cars, etc.), and this blurs the effect.

arie

In the Year of the Dog, the Great and Powerful arie declared:
> Recently, I have acquired a DVD movie "Mamma Roma" by P.P.Pasolini
> issued by Criterion, which is famous for its high-quality digital
> remastering of old movie classics. The disk is anamorphic 16:9, and the
> image fills the screen of my 16:9 LCD display (BENQ, 32") in the
> Full-screen or Anamorphic mode, supposedly undistorted. To my great
> disappointment, when the movie gets to slow horizontal panning takes of
> a static landscape (there are quite a few of them in the film), I see
> gradual distortion of the objects in the frame as they cross the screen
> from, say, the right margin to the center and then to the left margin.
> This effect is very disturbing to eyes.

This has nothing to do with the DVD -- it's how the movie was filmed.


35mm film, which most movies are shot on, have a squarish frame. To
create a widescreen image, there are two main methods. The first is
to shoot "flat" and then crop off the top and bottom of the frame to
the intended aspect ratio. The second is to use anamorphic lenses,
which capture a wide vista and compress it horizontally to fit on
the 35mm film. When it's projected in theater, a lens is used which
reverses the process. (Note that "anamorphic" in the sense of lenses
is completely different from "anamorphic enhancement" on DVDs.)

Anamorphic lenses -- and this is especially true with the earliest
ones -- create distortions that become noticeable when the camera
pans around.

--
Sean O'Hara | http://diogenes-sinope.blogspot.com
Leela: Uh, Professor, are we even allowed in the Forbidden Zone?
Professor Farnsworth: Why of course! It's just a name. Like the
Death Zone, or the Zone of No Return. All the zones have names like
that in the Galaxy of Terror.
-Futurama

Thank you, Sean.
I think you are right. I observed this phenomenon on another Pasolini's
movie, "Gospel according to St. Mathew"released by Tartan. Probably,
there was a problem with the lenses he used at that time (about
1962-63)

Arie

Sean O'Hara wrote:
> In the Year of the Dog, the Great and Powerful arie declared:
> > Recently, I have acquired a DVD movie "Mamma Roma" by P.P.Pasolini
> > issued by Criterion, which is famous for its high-quality digital
> > remastering of old movie classics. The disk is anamorphic 16:9, and the
> > image fills the screen of my 16:9 LCD display (BENQ, 32") in the
> > Full-screen or Anamorphic mode, supposedly undistorted. To my great
> > disappointment, when the movie gets to slow horizontal panning takes of
> > a static landscape (there are quite a few of them in the film), I see
> > gradual distortion of the objects in the frame as they cross the screen
> > from, say, the right margin to the center and then to the left margin.
> > This effect is very disturbing to eyes.
>
> This has nothing to do with the DVD -- it's how the movie was filmed.
>
>
> 35mm film, which most movies are shot on, have a squarish frame. To
> create a widescreen image, there are two main methods. The first is
> to shoot "flat" and then crop off the top and bottom of the frame to
> the intended aspect ratio. The second is to use anamorphic lenses,
> which capture a wide vista and compress it horizontally to fit on
> the 35mm film. When it's projected in theater, a lens is used which
> reverses the process. (Note that "anamorphic" in the sense of lenses
> is completely different from "anamorphic enhancement" on DVDs.)
>
> Anamorphic lenses -- and this is especially true with the earliest
> ones -- create distortions that become noticeable when the camera
> pans around.
>
> --
> Sean O'Hara | http://diogenes-sinope.blogspot.com
> Leela: Uh, Professor, are we even allowed in the Forbidden Zone?
> Professor Farnsworth: Why of course! It's just a name. Like the
> Death Zone, or the Zone of No Return. All the zones have names like
> that in the Galaxy of Terror.
> -Futurama