Widescreen with SD video

This page grew out of trying to explain how to convert between Standard Definition 4:3 and anamorphic 16:9 pictures in Final Cut Pro and Final Cut Express. It has since been updated with basic info on terminology we all should know to avoid confusion when discussing these concepts, some HD info and a discussion on the pros and cons of letterboxing your widescreen content.


Rabbe Sandelin
Helsinki, Finland

To ease working with widescreen in the video world, let's get some terminology and facts straight:


Aspect ratio The relationship between the width and height of any picture or image
(4:3 • 16:9 • 2.35:1 and so on). It is a shape. It tells you nothing about the content, the physical size of the image or how it was aquired.
Frame The acquisition or delivery media's actual maximum "physical" size. With film, you usually speak of the width of the film strip, or the height and width of the frame.
In video the physical aspects of the tape or hard drive medium are of course irrelevant. With video you'll want to know the frame's resolution.
Resolution A frame's pixel amount expressed as horisontal x vertical pixels
(720x576, 1920x1080 and so on).
Widescreen A moving picture with a wider aspect ratio than 4:3.
Anamorphic Horisontally squeezing a picture with a widescreen aspect ratio onto a 4:3 frame (widely used since the 1950's with motion picture film - visit The Widescreen Museum).
Letterboxing Scaling down a widescreen picture (anamorphic or not) to fit a 4:3 frame or display.

The discussion below uses these terms. If you feel lost - refer back to the list.

Standard SD video formats
These include pro formats like DigiBetaSX and prosumer formats like DV (and even old analog formats like VHS or Hi8). They employ a video frame that always has an aspect ratio of 4:3.

The resolution of the frame differs somewhat between NTSC and PAL regions (as does the frame rate). As an exemple, PAL DV has a resolution of 720x576.

There is no true 16:9 resolution for standard video, including DV, even though some newer DV cameras are being marketed as "true" 16:9 (in reality, only their picture sensors have a 16:9 aspect ratio).

Standard formats use anamorphic techniques to get a widescreen 16:9 picture - i.e the final displayed picture has a wider aspect ratio than the video frame.

High definition HD video formats
These include very high end formats like D-5 HD, HDCAM and Viper FilmStream, and also the new affordable prosumer formats HDV and DVCPro HD.

Most are true 16:9 all the way. If you count their vertical and horisontal pixels (and there are a lot of them), you end up with a frame that from the outset has a 16:9 ratio. (To cut bandwidth when recording, HDV and DVCPro HD utilize some internal tricks involving an anamorphic squeeze - but there is no 4:3 option).

The high-end and the prosumer formats differ most on compression (The Thomson Viper outputs 88 times more data than Sonys HDV camera). The prosumer formats are heavily compressed with MPEG2 and so have some, at least initial, problems with quality and editing.

There are a two HD frame resolutions, but the resolution is the same both for NTSC and PAL regions. The frame rates differ between NTSC and PAL just like with SD video.

VERY IMPORTANT: Widescreen 16:9 in Standard Definition video really only happens when
the picture is finally displayed, not anytime sooner. The SD video frame is always 4:3.

To ease editing in Final Cut, the anamorphic 16:9 picture can be be displayed correctly in the Canvas
by checking the "Anamorphic 16:9" box in the Sequence settings).

So what scenarios can we expect when we start experimenting
with widescreen on a standard definition SD camera?

Here we have a nice scene with 3 differently coloured balls on a grey table. Note the lovely symbolism of RGB...
- You know - Red, Green and Blue - that's the primary colors of... GET ON WITH IT!
Ok, now you whip out your... camera...
4:3 mode
Acquisition Recording Displaying
Your camera is in 4:3 mode.

(If your camera has a 16:9 sensor, it basically uses only the middle part of the sensor).

No problem here. The CCD picks up the scene and records it on the 4:3 video frame.
Your old regular 4:3 display/monitor/tv set displays it normally. Your 16:9 set shows black bars at the left and right side (unless you use your remote to cheesily distort the picture to fill the screen)

Click here for a workflow if you want to convert this kind of clip or sequence to
anamorphic widescreen 16:9 in Final Cut

"16:9", "Movie mode", "Letterbox" (or whatever your camera wants to call it)
Acquisition Recording Displaying
Almost all DV cameras with 4:3 sensors have this. They simply mask the upper and lower part of the scene to make a 16:9 picture area...
(some cameras even stop here)
...and then stretch the result vertically to fill the 4:3 video frame. Alright - it can now be called anamorphic 16:9.
A bit in the video stream tells the 16:9 tv set to stretch the picture horisontally to the 16:9 ratio. The result is to all intents and purpouses anamorphic 16:9, although a lot of the original resolution of the camera sensor is gone.
Anamorphic 16:9
Acquisition Recording Displaying
1. You use an anamorphic lens in front of the camera lens, or

2. You have a camera with a 16:9 sensor.

The camera now "sees" a 16:9 picture, incorporating more of the scene from the left and from the right.

1. The lens squeezes the 16:9 picture horisontally to fit the 4:3 video frame which will be recorded to tape, or...

2. The camera electronics squeezes the image from the 16:9 sensor to fit the 4:3 video frame.

This is what anamorphic means. You squeeze in more picture in your normal 4:3 frame.

Again your 16:9 display/tv set automatically stretches the 4:3 frame to fit the whole picture area. You use all available resolution in your camera.

To avoid confusion - don't call this kind of video footage "Letterboxed". It can be letterboxed to fit a 4:3 display in two ways: when exhibiting the picture (preferably with the automatic scaling by a DVD player or a similiar device), or by the procedure outlined in the link below:

Click here for a workflow if you want to convert anamorpic 16:9 clips
(like the two examples above) to letterboxed 4:3 in Final Cut

for distribution to 4:3 in situations where you are absolutely sure the letterboxing can't be done automatically by a dvd player, satellite set, DTV box and so on.

Additional discussion: Why letterbox a beatuiful anamorphic 16:9 picture in the first place?

Well, some people tell you it's the only way you can distribute a 4:3 version of your widescreen content.
As with almost all "truths" in video land, they would be both right and wrong. It all depends on were the content will end up, and there are a lot of scenarios.

But in my mind there really shouldn't be any need for it anymore. Here's why:

If your anamorphic 16:9 content lands on a DVD disc, the DVD player will automatically letterbox the picture to fit a 4:3 tv set (assuming that the user has been savvy enough to tell the DVD player that the display is in the shape of 4:3).

The above is true also for broadcasts (at least here in PAL land): the digital DTV box does the same scaling if you tell it to, and if the broadcaster also broadcasts traditional analog, the broadcaster will letterbox the content for the analog signal. The same goes for satellite transmissions.

I know there is a school of thought who says the automatic letterboxing in DVD players is so bad that you HAVE to make a letterboxed version of your own.

I think it might have been true five years ago but the scaling algorithms should be up to par now even on the cheapest DVD players.

I also think it's a terrible waste of time and effort in post, and a waste of precious space on a DVD disc. Space which could be used to beef up the data rate of the 16:9 content. And if your letterboxed 4:3 version ends up as the ONLY version on a DVD or in broadcast, you will make the owners of 16:9 sets very very angry - they will now have to manually zoom up the letterboxed picture to fill the screen, with a terrible loss of resolution as a result.

Anyway, I think the only scenario were you would letterbox in Final Cut would be for:

1. Distribution to VHS or other analog formats were you know the recipients have 4:3 sets (By the way, all newer European 4:3 sets can also do the letterboxing from anamorphic 16:9)

2. Dealing with a stubborn, backwards broadcaster who broadcasts everything in 4:3, doesn't have or doesn't know how to use equipment to letterbox the 16:9 picture, or simply is asking for a 4:3 version for whatever reason.


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