[Tig] 2.55 dimensions

Marc Wielage mfw at musictrax.com
Thu Nov 29 03:31:52 GMT 2012

On 11/28/12 5:36 PM, "David Bernstein" <d_bernstein2000 at yahoo.com> wrote:

> Does anyone happen to have any historical knowledge or documentation regarding
> the specific dimensions of the early CinemaScope 2.55 format? For example,
> according to RP40 the size of an anamorphic 2.39 image is 0.690 in. x 0.825
> in., within the Academy frame. But the 2.55 aspect ratio was used before the
> implementation of optical sound so it exposed more of the frame width, and had
> a different center, and I'm wondering if anyone has ever come across the
> numerical formula of that particular format. Was there ever a framing chart
> for that, for projector line-up?

Hi, David.  My memory is that this was covered in the AMERICAN


The anamorphic squeeze is identical between 2.40 and 2.55, since the only
difference is the optical track (I think it was "MagOptical" after 1958).

The dimensions of the matte size are documented, and I think the rest is
just making sure the image fits left to right and the splice lines don't
show (which you already know).  I've never seen an official SMPTE 2.55
framing chart, and even the 2.39 alignment films were discontinued some
years ago.  Here's a list of what SMPTE had at one time:


We dealt with 2.55 a lot on all the early CinemaScope films for Fox and
Columbia/Sony at Complete Post in the 1990s, and I did quite a few of those
transfers myself.  My general rule of thumb was to maximize image area
whenever possible, and hope that the DRS people were willing to clean up the
splice-lines when the budget warranted it.

--Marc Wielage
  occasional colorist

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