2.35:1 Within 16 x 9
Published : 28th March 2005
Is there a standard practice for mastering 2.35:1 movies to 16x9 HD? Is the HD image typically squeezed or letterboxed? Common sense tells me it would preserve the most information to master squeezed into 16:9, and then letterbox upon downconvert for the DVD release. I'm curious what the studios typically do.
In a related question, what is the standard delivery aspect ratio for digital projection of 2.35:1 films? Is it again squeezed into 16x9 and optically unsqueezed during projection, or is it more common to letterbox. Obviously, digital projection is limited and there are multiple ways to go about it, but I was curious if a common practice has developed.
Michael A. Nash
DP - Pasadena, CA
It's normal to use a letterbox for a 2.35 image on a 16:9 recording, whether HD or standard def.
DLP-Cinema projectors have a 1.5X anamorphic and 1.9X anamorphic projector lens to handle 1.85 and 2.35 movies, since the chips are nearly square, so a 16:9 signal is basically squeezed onto the chip and unsqueezed by the projector lens even for normal 16:9 / 1.85 images. So in this case, you could create an HD master where 2.35 is squeezed to fill 16:9 and then use the 1.9X anamorphic projector lens to show it. However, I've found at various festivals that not all DLP-Cinema projectors come with the 1.9X anamorphic lens so it's a good idea to bring a 2.35 letterboxed version as well to the screening just in case. You can use the 1.5X lens and crop & zoom the image to fill the 2.35 screen, although this will cause a 30% loss of screen brightness.
David Mullen, ASC
Michael Nash wrote:
class="style9" >Is the HD image typically squeezed or letterboxed? Common sense >tells me it would preserve the most information to master squeezed into >16:9, and then letterbox upon downconvert for the DVD release.
You are on the right track Mike. The 2.35 image is squeezed to fit into the HD 1.78 aspect ratio. As you mentioned, two things can happen on the way to DVD. The image could be "hard matted" or letterboxed for DVD...or better...the DVD can be authored to accept the squeezed 1.78 image.
When the DVD is played back on a 16x9 display it will fill the entire frame (of course you will still get small black bar at the top and bottom of the screen). With the hard matte a 16x9 display would place the image in the centre of the screen with large grey or black borders to the left and right of the image. Some monitors will allow the user to blow-up the image to fit the screen but then resolution is lost.
As far as what is common for studios...though it's becoming less and less common, whether the DVD is prepared "anamorphically" or letterboxed depends on the producers knowledge of the process. Although most recently produced DVD’s with a 2.35 aspect ratio seem to be anamorphically processed. Hope that helps!
Dominic H. White