Both the history and the modern revision of the title safe and action safe boxes that can be displayed in most video editing software are authoritatively explained in a document put out by the National Association of Broadcasters (NAB) in 2010 (emphasis mine):

From the early days of film and television, it has been recognized that not all of the information contained in the original image frame will necessarily be presented to the viewer. In television, the principal limitation has been the use of overscan in the viewer‘s receiver.

 

In 1957, the SMPTE Journal included a paper entitled Television Receiver Picture Area Losses, in which the author, Charles Townsend, describes research conducted at NBC‘s WRCA-TV in an effort to determine the extent of the broadcast image that was actually seen in viewers’ homes. The paper is reproduced in Annex B. Note that the safe area the author suggests is based on the assumption that all elements within the safe area will be viewable on at least 85% of receivers; no attempt is made to ensure viewability on 100% of receivers.

Television broadcast technology and consumer television equipment strangely stayed the same for many (more than 30) years, and then dramatically changed over the course of a decade or so. Now things are very different from the original study, and so the safe areas have had to be updated.

Later on in the document linked above, the current standard for image safe and title safe boxes is summarized:

SMPTE ST 2046-1 defines the Safe Action Area as a rectangle that is 93% of the width and 93% of the height of the Production Aperture (or 720 x 480 in the case of 480-line formats) and concentric with it. The Safe Title Area is defined as a rectangle that is 90% of the width and 90% of the height of the Production Aperture (or 720 x 480 in the case of 480-line formats) and concentric with it.

The EBU (European Broadcasting Union) has specified the exact same safe areas in their most recent document on the subject. The EBU uses the term Frame Raster Edge instead of Production Aperture and Graphics Safe Area instead of Title Safe Area.

Note: SMPTE stands for "Society of Motion Picture and Television Engineers", which is a body that has determined and published specifications for TV and film technology for a very long time.

Both the history and the modern revision of the title safe and action safe boxes that can be displayed in most video editing software are authoritatively explained in a document put out by the National Association of Broadcasters (NAB) in 2010 (emphasis mine):

From the early days of film and television, it has been recognized that not all of the information contained in the original image frame will necessarily be presented to the viewer. In television, the principal limitation has been the use of overscan in the viewer‘s receiver.

In 1957, the SMPTE Journal included a paper entitled Television Receiver Picture Area Losses, in which the author, Charles Townsend, describes research conducted at NBC‘s WRCA-TV in an effort to determine the extent of the broadcast image that was actually seen in viewers’ homes. The paper is reproduced in Annex B. Note that the safe area the author suggests is based on the assumption that all elements within the safe area will be viewable on at least 85% of receivers; no attempt is made to ensure viewability on 100% of receivers.

Television broadcast technology and consumer television equipment strangely stayed the same for many (more than 30) years, and then dramatically changed over the course of a decade or so. Now things are very different from the original study, and so the safe areas have had to be updated.

Later on in the document linked above, the current standard for image safe and title safe boxes is summarized:

SMPTE ST 2046-1 defines the Safe Action Area as a rectangle that is 93% of the width and 93% of the height of the Production Aperture (or 720 x 480 in the case of 480-line formats) and concentric with it. The Safe Title Area is defined as a rectangle that is 90% of the width and 90% of the height of the Production Aperture (or 720 x 480 in the case of 480-line formats) and concentric with it.

The EBU (European Broadcasting Union) has specified the exact same safe areas in their most recent document on the subject. The EBU uses the term Frame Raster Edge instead of Production Aperture and Graphics Safe Area instead of Title Safe Area.

Note: SMPTE stands for "Society of Motion Picture and Television Engineers", which is a body that has determined and published specifications for TV and film technology for a very long time.

Both the history and the modern revision of the title safe and action safe boxes that can be displayed in most video editing software are authoritatively explained in a document put out by the National Association of Broadcasters (NAB) in 2010 (emphasis mine):

From the early days of film and television, it has been recognized that not all of the information contained in the original image frame will necessarily be presented to the viewer. In television, the principal limitation has been the use of overscan in the viewer‘s receiver.

In 1957, the SMPTE Journal included a paper entitled Television Receiver Picture Area Losses, in which the author, Charles Townsend, describes research conducted at NBC‘s WRCA-TV in an effort to determine the extent of the broadcast image that was actually seen in viewers’ homes. The paper is reproduced in Annex B. Note that the safe area the author suggests is based on the assumption that all elements within the safe area will be viewable on at least 85% of receivers; no attempt is made to ensure viewability on 100% of receivers.

Television broadcast technology and consumer television equipment strangely stayed the same for many (more than 30) years, and then dramatically changed over the course of a decade or so. Now things are very different from the original study, and so the safe areas have had to be updated.

Later on in the document linked above, the current standard for image safe and title safe boxes is summarized:

SMPTE ST 2046-1 defines the Safe Action Area as a rectangle that is 93% of the width and 93% of the height of the Production Aperture (or 720 x 480 in the case of 480-line formats) and concentric with it. The Safe Title Area is defined as a rectangle that is 90% of the width and 90% of the height of the Production Aperture (or 720 x 480 in the case of 480-line formats) and concentric with it.

The document has appendices detailing actual pixel counts for sample resolutions.

Note: SMPTE stands for "Society of Motion Picture and Television Engineers", which is a body that has determined and published specifications for TV and film technology for a very long time.

Both the history and the modern revision of the title safe and action safe boxes that can be displayed in most video editing software are authoritatively explained in a document put out by the National Association of Broadcasters (NAB) in 2010 (emphasis mine):

From the early days of film and television, it has been recognized that not all of the information contained in the original image frame will necessarily be presented to the viewer. In television, the principal limitation has been the use of overscan in the viewer‘s receiver.

In 1957, the SMPTE Journal included a paper entitled Television Receiver Picture Area Losses, in which the author, Charles Townsend, describes research conducted at NBC‘s WRCA-TV in an effort to determine the extent of the broadcast image that was actually seen in viewers’ homes. The paper is reproduced in Annex B. Note that the safe area the author suggests is based on the assumption that all elements within the safe area will be viewable on at least 85% of receivers; no attempt is made to ensure viewability on 100% of receivers.

Television broadcast technology and consumer television equipment strangely stayed the same for many (more than 30) years, and then dramatically changed over the course of a decade or so. Now things are very different from the original study, and so the safe areas have had to be updated.

Later on in the document linked above, the current standard for image safe and title safe boxes is summarized:

SMPTE ST 2046-1 defines the Safe Action Area as a rectangle that is 93% of the width and 93% of the height of the Production Aperture (or 720 x 480 in the case of 480-line formats) and concentric with it. The Safe Title Area is defined as a rectangle that is 90% of the width and 90% of the height of the Production Aperture (or 720 x 480 in the case of 480-line formats) and concentric with it.

The EBU (European Broadcasting Union) has specified the exact same safe areas in their most recent document on the subject. The EBU uses the term Frame Raster Edge instead of Production Aperture and Graphics Safe Area instead of Title Safe Area.

Note: SMPTE stands for "Society of Motion Picture and Television Engineers", which is a body that has determined and published specifications for TV and film technology for a very long time.