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Re: Film safe action/title



Martin,

In answer to your question it seems that what you are asking for is the
projection aperture size. Let me see if I can explain. 

As you know the movie camera photographs an image that, depending on the
film size, has known dimensions. For 16 mm the image photographed is 0.404"
x 0.295". This image when put into a 16 mm motion picture projector will
display this image through  a slightly smaller aperature that is 0.373" x
0.272". That's the image that will be enlarged by the projection lens and
projected onto a white wall. Typically a screen that will accept this image
will be framed in black and this projected image, slightly larger than the
white part of the screen (overscaned), will totally fill the white part of
the screen. This is done so that any dust or hairs on the edges of the
aperture plate, the gate of the projector, will be masked.

This image minus the small amount lost on the black frame is what you will
see on the screen. Depending on the amount of overscan it is probably
around 2% + or - 1%.

One would think that that projected aperature (0.373" 0.272") would be the
image scanned in the telecine but most operations will scan to SMPTE RP
27.3 specifications which calls for  an scanned aperture of 0.368" x
0.276".  In the theater, however, the image is projected with the 0.373" x
0.272".

The viewfinders in most cameras have a glass reticule that tells the
cinematographer what will be projected on the screen and so he composes and
frames for that image size on the film even though the image actually
photographed is slightly larger (0.404" x 0.295").  There are also
reticules for TV as well with TV (transmitted, safe action and safe title).

Now we move into what is "Safe Action and Safe Title". These are TV terms
not motion picture theater terms. "Safe Action" is considered to be an area
5% less than the transmited or scanned image (0.368" x 0.276") or 0.331" x
0.248". Since TV sets overscan to fill the CRT screen "Safe Action"
gaurantees the viewer will see the action.

"Safe Title" on the other hand was created, and had it's roots from the
advertising agencies, to guarantee that no matter what kind of image
display device like a round CRT, a rectangular CRT with round corners, or a
flat display with square corners, the viewer if viewing text will always be
able to read it.
 
I don't beleive there are any set rules as regards to safe action or safe
title in the motion picture business as composition is the name of the
game, but in TV it is SMPTE RP 27.3. 

It's a known fact that OLD movies, made for the theatrical screen,
transfered to video using RP 27.3 when viewed on a standard TV will cut off
some of the titles and credits but the same film when viewed in the theater
are viewed as composed and there is no cut off of the action and titles.

Technically, in my opinion, think the projection aperature dimensions
should be used for the TV scanning of the film image. The days of scanning
an image 0.368" x 0.276" are fast comming to a close. Round CRT's are from
a bygone era.

The TV set manufacturers say that on a production line tolerances are
around 10%. To reduce these tolerances would be costly to the consumer.
That's one reason that professional monitors cost more than TV sets.
Digital television and display technologies, however, are helping somewhat
in this regard as they have fixed pixel arrays. In the NTSC analog system
as blanking widths changed the pictures horizontal size changed. Verticle
blanking changed the verticle height of the image as well as the number of
scan lines for the scanned image.

I don't think there is any "Safe Action and Safe Title" rules for film for
theatrical release (with no possiblity of being transfered to video). Only
good composition. Today that has been compromised to a certain extend
because film framed in 1.85:1 could be shown in 1.66:1 or 1.78:1 as an
example.

Jim Mendrala
Real Image Technology Inc.
  

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