Whats in the Picture: an Introduction to TV standards and Aspect Ratios
Television standards as we call them are the Encoding standards for the recording and reception of video “Synergy between the video and how we play it”.
The 3 Standards are:
NTSC= National television standards commitee
PAL= Phase Alternating Line
SECAM= Sequential Colour Memory
A TV’s video output is made up of 25 to 30 frames which display every second, each frame is made up of 625 scan lines (525 for NTSC 625 for PAL and SECAM).
NTSC is the TV standard of the Americas, it was created in 1941 as the standards for black and white TV broadcasts.
Strengths: there is less flicker and smoother motion in the video output because of higher frame rates and it produces less noise.
Weakness: the lower number of scan lines means the picture isn’t as clear as PAL and the contrast level poor. Colour levels can fluctuate from frame to frame.
PAL was created for UK broadcasting in 1961.
Strengths: has more scan lines so the pictures have higher picture detail, higher levels of contrast and better colour reproduction than NTSC.
Weakness: lower frame rate means the picture motion can appear to flicker more than 30 frames and colour saturation can vary from frame to frame.
SECAM was created in France in 1967, it is now an unpopular standard.
Strengths: the high number of scan lines means a good quality picture, the colour hues are in constant saturation and it has stable colour reproduction.
Weakness: like PAL there is more motion flicker and Pattern effects seem to crop up on the picture from time to time, there are also many many variants of SECAM from country to country alot of which are incompatible with one another.
Aspect Ratios by definition are the relationship between the width and the height of a film (or video) frame. An example of an aspect ratio would be Terminator 2 which has an aspect ratio 2.20:1. This means that the image is 2.2 times as long as it is high.
There are many different aspect ratios, and some cameras will only be able to film in certain aspect ratios. What follows is a few examples of popular types of aspect ratios.
Academy Standard 1.33:1 (or 1.37:1) it is also known as 4:3
one of the earliest aspect ratios was popular through out Hollywood’s “Golden age”.
It was used after silent films had fallen out of fashion. The NTSC used the Academy standard for TV screens as it transferring films to TV easier. A famous example of movie filmed in the academy standard would be Casablanca from 1942.
In the early 50’s widescreen cinema had become very popular which made life difficult for film makers as it required them to use specialised cameras and projectors which cost a lot of money, so they came up with a wider solution which was a new standard called Standard Flat. Many theatrical films use the Standard flat to this day, an example of a modern film would be Trainspotting which was released in 1996.
All feature films are shot on film reels. The drawback of this practise is that there is not as much room in the picture, so in order to widescreen you would need a wider film stock. In Anamorphic scope the film is shot with a “anamorphic” lens attached to the camera. An optic located inside the lens contracts the light waves together as they enter the lens. The image is then compressed on it’s horizontal axis, to half its original width. An example of this would be a 2.35:1 image would be compressed to 1.18:1. Later on when the movie is played back at the cinema the picture is stretched back out to its full width. An example of a movie filmed in anamorphic scope would be live action 101 Dalmatians from 1996.
1.66:1 / 1.85:1 / 2.0:1
More flexible than other film formats. It allows for more aspect Ratios. It was created in 1954 by engineers and Paramount. Filmed with a special camera mounted on its side. its image quality was better t
han a standard 33 mm, but it did require a special projector.
Movies shot in Vistavision include Vertigo, North by North West, White Christmas.
Widescreen in nature, the system originated in Canada at the Expo 67 fair in Montreal where a group of Filmakers/entrepreneurs designed a new system using a single powerful projector rather than multiple projectors that industry standard at the time. this revolusionised.
Movies shot in IMAX include Contagion, Real Steel, Puss in Boots.
This uses 3 cameras and interlocks the 3 images together which creates an extremely wide presentation in 2.60:1 but when its transferred to video it’s aspect Ratio becomes 2.35:1 as the film is reduced to a 35mm anamorphic print.
movies shot in Cinerama include How the West was Won, The Wonderful World of the Brothers Grimm, and Seven Wonders of the World.
All Images used came from Google images.