All About Aspect Ratio
Part 3 – When Less is More
If you have already read Part 2 of this article series, you will be aware of the issues that arise when widescreen film is transferred for viewing on narrower TVs. Compromises have to be made either to the original width of the film or to the size of the image on the TV. The compromise discussed in the preceding article was the Pan & Scan process, a method by which the width of the widescreen image is sacrificed in order to fill a narrow TV frame with the remainder of the image. The other process touched upon was the letterbox format, whereby the image is reduced vertically so that it fits on the screen in its entirely.
This is actually an oversimplification of the issue, as there are two other compromise techniques commonly used in filmmaking to accommodate the narrower aspect ratio of the TVs – soft matting (full frame transfer) of 1.85:1 movies, and Super 35 of 2.35:1 movies. These will be the subjects of this article.
Anamorphic films or anamorphic DVDs will be touched upon loosely in Part 3 and will be explained further in Part 4.
1.85:1 Movies can be Panned & Scanned or Open Matted
Pan & Scan
If the intended aspect ratio of a movie is between 1.66:1 to 1.85:1, there are two ways in which the original widescreen image can be modified for narrow TV screens. One of these is by using the Pan & Scan process as already discussed in Part 2, but the more common process is known as open matting, or full frame transfers. As a reminder, reproduced below is an example of a 1.85:1 movie that has been Panned & Scanned to fit on a standard 4:3 Television set.
Here’s an example from Sweeney Todd: The Demon Barber of Fleet Street (2007). In this scene, Todd Sweeney (Johny Depp - center) is about to engage in some musical action. In the full screen version we loose much of the background characters that are framing this image.
Full Frame (Open Matte)
Open matte is a filming technique that involves matting out the top and bottom of the film frame in the movie projector (known as a soft matte) for the widescreen theatrical release and then scanning the film without a matte (at Academy Standard) for a full screen home video release.
When a 1.85:1 movie is being shot, extra image is actually captured to that which the director and cinematographer intend to be shown in the movie theatre. This is usually at the top and the bottom of the image. When the image is being composed through the camera, markings on the viewfinder show the director and cinematographer what will actually show up theatrically, so that important image details are not left out of shot.
When it comes time to show the movie theatrically, the 1.33:1 print has a masking plate placed in the image path so that unwanted parts of the image are not shown in the theatre, and instead the audience sees what the director intended. This process is known as soft matting.
The above example shows the 2.35:1 cinema aspect ratio in yellow this is the image that will be projected at a theater when shown in widescreen. For 4:3 television transfer, the extra footage can be used that is contained within the red box. Without open matte filming, a pan and scan transfer of the widescreen version would have to work within the yellow box, cropping out much of the picture.
The key concept here is that there is indeed extra image available to that which is shown theatrically, and to that which was intended to be seen artistically by the director and the cinematographer. This extra image comes in handy when it comes time to transfer the movie to a TV format, as instead of losing image width, as with the Pan & Scan process, you can simply remove the mattes to get a 1.33:1 image. Thus, there is no loss of image, and indeed there is extra image shown.
- However, all is not as rosy as it would appear with this process, as two compromises have been made;
The image is no longer in the director and cinematographer’s intended aspect ratio. They composed their images to be seen at this aspect ratio, and this is compromised by the full frame process, losing artistic impact as a result. - Sometimes unwanted information can be seen in the opened matte sections of the image, such as boom microphones, camera tracks, and other things invisible at the theatrical aspect ratio.
Above Left - This is a still frame from Man with Two Brains (1983). This is how the movie appeared in theatres in its 1.85:1 aspect ratio.
Above Right –This is the same still frame after mattes have been removed. Note the extra picture shown at the top and the bottom of the screen. Note also the different feel of the images.
2.35:1 Films use Anamorphic Photography
As explained above, most film negative stock is actually 1.33:1 wide, but this has been adapted to widescreen use. In the case of 1.85:1 movies, a small amount of image resolution is sacrificed by simply discarding the top and the bottom of the image. This is not a problem in practice. However, for 2.35:1 movies, the situation is not as simple. If 2.35:1 movies were made simply by matting the top and the bottom of the image, 50% of the resolution of the film stock would be lost. By the time this reached the theatre, the result would be a very poor quality image projected onto the screen and an audience that is not too happy.
This problem has been resolved by the development of anamorphic photography. The processes involved have various trade names, but the common ones are Panavison and Cinemascope.
In these processes, a special lens is placed on the camera, which distorts the image. It squeezes images horizontally by a factor of 2 to 1. The entire film negative is used to capture the image. The film negative is 1.33:1 wide, but the image captured is actually 2.35:1 wide. If you look at the developed negative, the image appears tall and narrow. When the film is projected, a complementary lens is used to project the image, which expands the image back to the original 2.35:1. Thus, image quality is maintained as no area of the negative is wasted.
Films produced using this process must be Panned & Scanned when they are transferred to a narrow format. There is no additional picture information available, as the entire as the entire camera negative has been used up capturing the widescreen image.
2.35:1 Films can use the Super 35 Process
The Super 35 process is an attempt to achieve much the same goals for 2.35:1 films as the open matte process achieves for 1.85:1 movies - an acceptable presentation of a widescreen movie on a narrow TV screen.
A Super 35 image is photographed onto film stock which is the same shape as ordinary 1.33:1 film stock, but where the space normally reserved for audio tracks on the film stock is used for image.
The theatrical release print is made by matting a little under 1/2 of the original negative and then zooming in on the remaining image. For narrow TV images, again the image is opened up by removing the matte, although the sides of the image are also narrowed a little in the process.
There are a number of issues inherent in Super 35 cinematography and its open matte presentation. Firstly, since almost half of the original negative image is discarded when producing the theatrical print, the final resolution of the image is not as good as it would be with the conventional anamorphic process used for the production of 2.35:1 movies. The end result can be a very grainy looking theatrical image with poor image resolution.
There are also issues with the open matte TV presentation of the movie, more of an issue for special effects extravaganzas than it is for more straightforward dramatic or comedic movies. Special effects shots for movies are normally produced at a single aspect ratio, usually the theatrical aspect ratio. So, special effects shots for 2.35:1 movies are produced at 2.35:1 - to do otherwise would be a waste of resources and money for what is already a very expensive process. When it comes time for these shots to be prepared for display on narrow screens, unlike the conventional Super 35 shots which have additional image top and bottom which can be utilized, there is no additional image available to show for the special effects shots, so they need to be Panned & Scanned.
Closing Remarks
Hopefully all the above discussions of the different processes involved in producing narrow screen versions of widescreen movies will serve to explain a number of things you may have noticed in your journey through the widescreen projector wilderness.
The next topic to be covered in Part 4 of this series of articles is Anamorphic DVDs and Anamorphic Lens for Projectors.