A widescreen 1.85:1 image was created by cropping a standard
1.37:1 film. Cropping employed masking/covering the
top/bottom of the theater projector lens.
The unmasked area created the
image that filled the 1.85:1 theater screen. But masking
sacrificed the resolution of the forfeited surface of the
2.35:1 Cinemascope and 2.39:1 Panavision use an anamorphic camera
lens to squeeze a widescreen image within the 1.37:1
film frame. A reversing anamorphic projector lens
restored the 2.35:1 or 2.39:1 widescreen image on the theater
screen. The anamorphic process salvaged the film
resolution lost in the 1.85:1 masking process.
Masking and anamorphic processing saved theaters and the
They accommodated each ratio with a single film size, a
standard camera, standard projector, plus interchangeable
camera and projector lenses.
Digital Cinema Initiative (DCI) Digital Cinema
Digital projection has replaced film in movie
The digital distribution standard aspect ratio is widescreen
IMAX theaters present their exclusive films in a 1.90:1 or
1.43:1 aspect ratio.
The IMAX aspect ratio is not included in illustrated above.
TV Aspect Ratio
HDTV and UltraHDTV have an aspect
ratio of 1.78:1 (16:9).
However, this screen ratio must accommodate a 100-year old
library of different aspect ratios.
This accommodation initially arrived as:
1. Place the original image ratio within the 16:9
screen. Fill the unused screen with black or gray
2. Stretch the image to fill the
NTSC Anamorphic DVD
Anamorphic DVD squeezed widescreen images within the DVD 4:3
An anamorphic DVD was labeled as Enhanced for Widescreen or
Enhanced for 16:9.
The DVD player's anamorphic software restored the full
widescreen image on the HDTV screen.
The Blu-Ray disc has a 16:9 aspect ratio.
Blu-Ray does not have a
'fill-the-screen-option' for other aspect ratios.
Making a 'goose-bump' difference
My friend Steve maintained that everything makes a
difference. Aspect ratio can make a difference.
Expert management of aspect ratio
can add to a goose-bump generating experience.
Home theater projectors with large 90+ inch screens can manage
aspect ratios with a 'constant-height processor' and vertical
A constant-height processor fills a DLP, LYCOS, DILA, LCD
projector's 16:9 chip with a 2.35 or 2.40 image. It
squeezes the image laterally while maintaining its
height. An anamorphic lens slides over the projector's
native lens to reverse the 'squeeze' and fill a 2.35:1
To make a difference, automate the lens slide and masking with
the source aspect ratio. Given the constant height,
automated masking can smoothly unfold from 4:3 to 16:9, to
2.40 aspects ratios. This 'unfold' method fulfills an
impressive must-see-to-grasp goose-bump movie presentation.
The Land Of Forgotten Buzz-words.
This list of terms have lost or
are losing their relevance. Many were abused and used to
confuse and mislead innocent consumers.
Yeah, it happens. Review this list. Then consider
how a new slate of TV tech buzz-words will be used to confuse
consumers from sea to shining sea.
DVD 3:2 Pull-Down
Here's a golden oldie.
A movie frame rate equals 24fps. DVD equals 30fps.
The difference created a frame misstep and unwanted video
3:2 pull-down solved the issue. 3:2 pull-down repeated
every fourth frame of the film, which produced a rate of
DVDs included 3:2 pull-down instructions. DVD players
executed the instructions.
LCD Blur & Judder
This issue plagued LCD 60Hz HDTVs. LCD motion that
crawls in and out of focus is blur or judder.
Blur refers to slow LCD pixel response and back-light
problems. Judder is a 24fps versus 30fps
LCD 120Hz & 240Hz Processing
LCD TVs address blur with 120Hz and 240Hz processing.
Each process is available in an abundance of copyrighted
But each method includes more than a simple frame rate
The digital HDTV frame rate equals 60fps. 120Hz
processing inserts one extra frame between each original
The extra frame comes in one of two versions; a black frame or
a frame of interpolated motion.
The eye recognizes 'Constant ON' of LCD back-lighting as blur
during frame transitions. The inserted black frame
reduces the effect.
The interpolated frame predicts and creates smoother motion
from frame to frame. 120Hz processing reduces blur
caused by slow LCD pixel response.
240Hz inserts three frames between each of the original 60
240Hz inserts a combination of black and interpolated frames.
Each manufacturer determined
the number of black versus interpolated-frames.
Multiple Hz processing also reduces judder because 24fps
divides nicely into 120 or 240 fps.
Back-light Scanning ... more blur reduction
LCD TV back-light scanning synchronizes 'blinking
back-lights' with LCD TV frame transitions.
This 'blinking-back-lighting' is much like the film shutter
gate of a movie theater projector.
This 'blinking-gate' reduces the glare of constant 'ON'
No Blur, No Judder, No More Plasma
Plasma TV is long gone. Until OLED TV arrived, plasma
was the better TV technology. Its decisive advantage
was a significantly lower black level, which delivered
better contrast. Also, plasma did not suffer from
blur or judder. Plasma TV had no need for LCD
120Hz or 240Hz type processing
Plasma did offer 600Hz
sub-field-drive and 2500Hz focused-field-drive.
Both were often incorrectly viewed as a version of LCD 120Hz
and 240Hz processing.
focus-field-drive had nothing to do with blur or judder.
Instead, both created tighter control of pixel-light emission.
600Hz sub-field-drive improved pixel clarity with up to 10
light-pulses per frame. Each pixel ascended to full-lit
amplitude in less than 1.67ms.
Put this in perspective, LCD response equals 4 to 12ms.
A sub-field is a single pulse period.
Each frame consists of 10 periods. Pulses drove the
illumination of plasma pixel phosphor.
Each period is pulsed or
not-pulsed. A pixel begins to illuminate with the 1st
pulse. The total brightness is equal to the sum of the
This process offers thousands of shades of gray, which
expanded the grayscale and color gamut. As for the
moniker 600Hz -- 10 sub-fields by 60fps
equals 600 sub-fields per second. Hence 600Hz
2500Hz focus-field-drive also
drove brightness with pulses. However, 2500Hz-ffd
produced all of its light in the last 3 sub-fields.
That created a response time of only 0.4ms. The faster
window of illumination was much as shutter speed in
Also, given the first 7 to 8 sub-fields were off-condition,
contrast vastly improved. The focus-field-result was a
sharper, clearer image.
Dividing 1 second (1000ms) by 0.4ms derived the 2500Hz