| DVD Roundup September 2005
All About Aspect Ratios --
Part One
People have all kinds of questions and frustrations
about how movies appear on their home-theater systems. Everyone has his or her own ideas
about what’s right and what’s annoying. But many are annoyed by something they
don’t even understand. I’ll try here to get everyone on the same page -- or at
least the same screen.
Most home-theater enthusiasts -- those who love movies and
love watching them on a system they have carefully put together after months or years of
research -- want to see the entire film frame used by the director: the same frame shape,
or aspect ratio, shown in movie theaters. For those who complain about the movie
not filling their home screens, read both parts of this article and see if they change
your opinion.
To understand why all movies can’t always fill
your home screen, whether you’re watching a vintage Zenith from the 1960s or the
latest fixed-pixel projection setup, we first need to understand what has been going on in
the film industry since the early days of silents up to the present. Part Two of this
series will show you how these different aspect ratios fit home-theater video displays.
The silent decades
 In the early days, when films were
silent, things were simple. Every movie and movie screen had the same shape. The film used
in cameras was exposed in frames whose shape had a 1.37:1 ratio of width to height. The
film negative was printed onto projection film of the same frame size and aspect ratio. In
short, the width of the negative frame, print frame, and of the projection screen was
always 1.37 times the height. This means that a screen in a small-town theater that might
have been 15’ wide was almost 11’ tall, and a big-city movie palace’s
25’-wide screen would have been 18.2’ tall -- both had the same aspect ratio of
1.37:1. Measure any of those screens, divide the width by the height, and you would always
have come up with the same number: 1.37.
Enter talkies
From the early days of silent films, everyone knew that
adding sound to movies was inevitable. Early experiments synchronized phonograph records
to film to provide sound to the whole theater through a single unamplified
"concert" horn, and there were other inelegant attempts to make the spoken word
part of the fun. It wasn’t until the dawn of electronic recording technology in the
mid-1920s that it finally became practical to add sound to movies. Within a few years,
silent films had entirely disappeared.
 The easiest way to synchronize sound
and image turned out to be recording the sound right on the film itself, on a special
optical "sound track." The industry loved the technology, because it was printed
right along with the movie frames when a film was copied for theatrical release. Looking
like an oscilloscope display of sound captured by a microphone, the optical
soundtrack robbed some space from the film image, which now
had to be narrower so that the soundtrack would fit. As a result, the new film aspect
ratio was 1.33:1 (or 4:3). On that small-town movie house with the 15’ x 11’
screen, a new talkie would be projected 14.6’ wide, or with a loss of 2.5" on
each side -- pretty insignificant. The 25’-wide big-city screen lost a total of
0.8’ (9.6") of width. This left thin white bands of unused area at the right and
left edges of the screen, though this was inconsequential -- at the time, just about every
theater in the country had screen curtains that could be adjusted to cover these areas.
The 1.33:1 ratio became known as the Academy Standard.
The TV revolution begins
 When television began to appear not
long after the end of World War II, the shape of the TV screen was dictated by the shape
of the film images then being shown. Virtually all films were made in the standard 1.33:1
aspect ratio, so that was the ratio adopted by TV manufacturers. When films began to be
broadcast on TV in the early 1950s, their frames perfectly filled the TV screen, and for a
few years everyone was happy. But TV so fascinated the American public that movie
attendance soon began to slip. Had this trend continued, film studios and theaters would
have folded faster than bad poker players holding pairs of deuces.
The widescreen revolution
 Hollywood then went through a period
of hand-wringing, self-flagellation, finger-pointing, and despair over the small but
all-conquering TV screen. One studio exec more forward-looking than his peers stole a
promising concept from an underling who should have been running the studio:
"TV is small -- people will come to see something really big." The race for
big-screen excitement began. Aspect ratios went all the way to 2.66:1 before settling back
to a more reasonable 2:35:1 for epics and blockbusters. The "big" trick worked.
The public loved the widescreen experience, and continued to come to see new movies in
great numbers.
Where we are today
 The most popular aspect ratio for new
movie releases today is 1.85:1. This format is widely used for dramas, comedies, and
action films with smaller budgets than the blockbusters. Blockbusters, epics, and
special-effects extravaganzas are still often released in 2.35:1, though quite a few
different ratios are used that fall between 1.85:1 and 2.35:1. Aspect ratios below 1.85:1
are called "flat" and are cropped from a standard Academy frame. Larger ratios
are mostly anamorphic. In an anamorphic image, the aspect ratio is horizontally squeezed
and distorted during filming, then expanded to the full width of its particular aspect
ratio by a special anamorphic lens in the projector itself.
 1.66:1 runs a little behind 1.85:1 in
total number of films made, but is very commonly used for animated films as well as dramas
and comedies. Fans of older films will see much greater variation in the aspect ratios
listed on DVD boxes because of all the variations released in the 1950s through the 1970s,
plus the original 1.37:1 and 1.33:1. European aspect ratios can also vary from American
ones.
How do theaters handle so many different image sizes?
Theater owners have to deal with movies of different sizes,
along with all the other things they show us when we go to see a movie: movie trivia
quizzes that play on slide projectors, announcements about turning off cell phones and the
treats available at the snack bar, previews of upcoming releases. The chance of all of
these shorts being the same aspect ratio as the feature film is about zero. In the better
theaters, the projectionist zooms in on each image from a different source so that the
image fills the screen from top to bottom. If the image’s width doesn’t fill the
screen from left to right, the operator draws the curtains to cover the unused portions.
Cheesier movie theaters just leave the unused white portions of the screen exposed for the
audience to ignore as best they can.
Next month I’ll talk about how to deal with all of
these different aspect ratios in a home theater.
…Doug Blackburn
db@hometheatersound.com |
