Definition

cinema pulldown 3:2 (telecine)

Part of the Electronics glossary:

Cinema pulldown 3:2 is an algorithm for matching the slower frame rate of film to the faster refresh rate of a 60 Hz television. Cinema pulldown is also called telecine or 3:2 pulldown. 

The standard frame rate for film is 24 frames per second (fps). This means that if you go to the movies, your eyes are shown 24 frames of film each second. 

Many current and older televisions have a fixed refresh rate of 60Hz.  This means that if you are watching such a TV, your eyes are shown the digital equivalent of 60 frames each second. Always.  

When you are watching a film on a 60Hz television, software in the TV or DVD player detects the incoming signal and fills in the missing 36 frames by repeating frames that your eye has already seen.

Ideally, each frame would be repeated the same number of times. The problem is that 24 doesn't divide evenly into 60.  If each frame is repeated twice, that's only 48 frames per second. There will still be 12 missing frames. That's where the 3:2 ratio comes in. To ensure that there will consistently be 60 frames per second, the first frame is displayed on the TV screen 3 times and the second frame is displayed 2 times. The following frame is repeated 3 times, the next one 2 times, etc. throughout the film.

Because alternating frames are not repeated in a consistent manner, however, the picture on the television screen is actually a little jittery. In TV-vendor lingo, this is called judder.  Most of us don't notice judder because a second goes by very quickly and our brains adjust to it.

Vendors who are producing televisions for 3-D viewing, need to alternate frames in a consistent manner to get the best possible picture.  One way for them to do this is increase the refresh rate on newer LCD televisions to 120Hz.  Because 24 divides evenly into 120, alternating frames can be repeated in a consistent manner (5 times each).  This consistency produces a more accurate picture.  

See also: soap opera effect, Fast Guide to Flant Panel TV

Learn more about 3:2 pulldown:

ProjectorPeople.com explains more about Cinema Pulldown and reverse 3:2 pulldown.

This was last updated in December 2010
Posted by: Margaret Rouse

Related Terms

Definitions

  • geo-fencing (geofencing)

    - Geo-fencing is a feature in a software program that uses the global positioning system (GPS) or radio frequency identification (RFID) to define geographical boundaries. A geofence is a virtual barr... (WhatIs.com)

  • bandwidth

    - Definition: Learn what bandwidth is and how the term is used as a synonym for signal frequency range, data transfer rate and capacity. (SearchEnterpriseWAN.com)

  • quad-core processor

    - A quad-core processor is a chip with four independent units called cores that read and execute central processing unit (CPU) instructions such as add, move data, and branch. (WhatIs.com)

Glossaries

  • Electronics

    - Terms related to electronics, including definitions about electrical components and words and phrases about computers, laptops parts, digital cameras, televisions and home appliances.

  • Internet applications

    - This WhatIs.com glossary contains terms related to Internet applications, including definitions about Software as a Service (SaaS) delivery models and words and phrases about web sites, e-commerce ...

Ask a Question About cinema pulldown 3:2 (telecine)Powered by ITKnowledgeExchange.com

Get answers from your peers on your most technical challenges

Tech TalkComment

Share
Comments

    Results

    Contribute to the conversation

    All fields are required. Comments will appear at the bottom of the article.