Film-Tech Forum ARCHIVE: Full Frame 1:33 or 1:37

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Posted by Bernie Anderson Jr (Member # 410) on 02-26-2001, 01:57 PM:

Films before 1953-54 were shown at what aspect ratio 1:33 or 1:37? On the RP40 it has lines for 1:37 but I've heard 1:33 being thrown around almost as if they're interchangable. I'm assuming up till sound everything was full frame. What year was the standards made? Any thoughts?

Bernie

Posted by Michael Hunt (Member # 772) on 02-26-2001, 02:10 PM:

Academy Silent was 1:1.33
Academy sound was 1:1.375 as shown on the very useful BKSTS Film Formats wallchart www.bksts.com

Unfortunately some people, including the British Film Institute, refer to Academy as 1.33, whether its sound or silent...

Posted by John Pytlak (Member # 331) on 02-26-2001, 02:47 PM:

Standard SMPTE 195 defines the "Style B" area as 0.825 x 0.602 inches. I have a Motion Picture Research Council document dated August 1955, that specifies the area as 0.825 x 0.600 inches (1.375:1). AFAIK, this had been the "Academy" area of 35mm prints with optical sound since the early 1930's.

In my copy of the December 1937 Journal SMPE, page 615, the "Report of the Projection Practice Committee" notes "...the dimensions of the standard projector aperture, which are 0.825 x 0.600 inch." In a meeting in July 1937, the SMPE Projection Practice Committee had reaffirmed that aperture size, rejecting a proposal by the Academy that it be made slightly larger with a shift in the centerline.

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John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Eastman Kodak Company
Research Labs, Building 69, Room 7419
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

Posted by Steve Guttag (Member # 268) on 02-26-2001, 06:04 PM:

1.37 is the standard as others have noted. It has be .602 x .825 inches for some time. Even going back to the silent era doesn't come up with 1.33!!! Silent apertures after 1910 seem to be uniformily .680 x .910 or about 1.34:1 (yes I have measured the fixed apertures of several period projectors of the era, including some old Simplex and Powers projectors)...all came out to .680 x .910 give or take a thousandth.

Now 16mm has been effectively 1.33:1 or 4:3 as the Video guys call it. (.286 x .380).

I just recently cut a set of special "Super Silent" plates (my term) that measure .725" x .945" . I will be looking into pre-1910 projectors to see how their apertures measure up. A trusted projector historian tells me they tended to be a little larger than later projectors.

Steve

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"Old projectionists never die, they just changeover!"

Posted by Leo Enticknap (Member # 534) on 03-05-2001, 01:55 PM:

Academy does seem to be referred to as '1-33' by English projectionists even though, as Michael Hunt points out, the specified projector aperture is nearer 1:1.37.

The only explanation I can think of is that the projector aperture is not quite as tall as some camera/printer apertures, in order to minimise the risk of showing a matte line on the screen.

BTW, I have never heard the phrase 'Academy Silent'. My understanding (most of which is taken from the articles in Raymond Fielding, 'A Technological History of Motion Pictures and Television') was that the silent camera and projector apertures in use immediately before the conversion conform to an SMPE standard published in 1917.

Sound-on-disc films continued to use this aperture, while early Movietone productions simply masked off an area of the film on the left hand side to make way for the optical track, resulting in a ratio of approx. 1:1.15. This lead to format chaos because cinemas were not fitted with adjustable masking in those days, whilst producers were forced into shooting two versions for disc and film sound releases (see Scott Eyman, 'The Speed of Sound'). It was because of this that AMPAS stepped in and suggested restoring the old frame dimensions by printing a thicker matte line between the frames on a combined print and using a shorter lens to magnify it to the same size.

Interesting thing is, with Dolby digital you could increase the picture and sound quality on modern films by going back to full-frame and 16fps. You'd have a better picture because of the bigger frame area, and there'd be no flicker if a three-blade shutter were used. Also you'd use 33% less stock per print which would reduce costs and benefit the environment (though I guess the stock manufacturers and labs wouldn't be too keen on the idea). OK there'd be 8 fewer perfs' worth of sound data per second, but if you printed data blocks on both sides of the film...

Posted by Aaron Haney (Member # 747) on 03-10-2001, 06:58 AM:

While we're on the subject, what's up with the "scope" aspect ratio? Someone please correct me if I'm wrong, but as I understand, the ratio was (after some initial experimentation) finally settled on at 2.35:1. Then, in 1971, the frame area was reduced just slightly to give more of a gap between frames, thus changing the ratio to 2.39:1, where it has remained ever since.

The thing is, I almost never see anyone refer to it that way. Lots of people who ought to know still call it 2.35:1. DVD is especially bad about it. I even see trailers of upcoming "scope" movies in Quicktime that have been carefully sized at a 2.35:1 (not 2.39:1) ratio.

So what's the deal, is it 2.39:1 or not?

Posted by John Pytlak (Member # 331) on 03-10-2001, 07:08 AM:

Standard SMPTE 195 specifies the current "scope" projectable image area as 0.825x0.690 inches. With a 2X anamorphic lens, that is 2.39:1 on the screen. You are correct that it has been many years since the area was 0.839x0.715 inches (2.35:1).

The slightly smaller area was adopted to reduce the visibility of the negative splice "flashes", and reduce the risk of showing the silver soundtrack application and DTS data track on the left side of the image.

I did a search of the SMPTE standards to document the history of the changes, which are posted on Marty Hart's "American Widescreen Museum" website:
http://www.widescreenmuseum.com/widescreen/apertures.htm

It says:

From 1957 through today, there have been a number of small changes to the anamorphic projector aperture recommended standards. John P. Pytlak of Eastman Kodak dug through countless back issues of the SMPTE Journal in order to provide the following chronology of the changes to the standards:

The March 1957 SMPTE Journal has PH22.104-1957, the standard for 2.55:1 anamorphic (no optical track), with an aperture size of 0.912 X 0.715 inches. Notice of withdrawal of this standard was in the January 1964 Journal.

The December 1957 SMPTE Journal has PH22.106-1957 for 2.35:1 anamorphic, with an aperture of 0.839 X 0.715 inches. It was unchanged in the September 1964 Journal. The November 1965 SMPTE Journal published PH22.106-1965 still with the 0.839 X 0.715 aperture size.

In the September 1970 SMPTE Journal, a new draft of PH22.106 was proposed, with an aperture size of 0.838 X 0.700 inches, to minimize the flashes at splices. This was republished as standard PH22.106-1971 in the October 1971 issue.

In the June 1976 SMPTE Journal, the two (flat and scope) projectable image area standards (PH22.58 and PH22.106) were consolidated into one standard and renamed PH22.195. The publication of PH22.195-1984 in the October 1984 Journal still had the scope area as 0.700 X 0.838 inches.

The June 1992 SMPTE Journal published a proposed revision, with a scope area of 0.690 X 0.825 inches. In August 1993, the standard was published as SMPTE 195-1993, with the current area of 0.690 X 0.825 inches. So August 1993 is when the two formats became the same width of 0.825 inches.