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reference materialRendering Widescreen Movies for Computer Screen & DVD

by Vonda Yarberry

Introduction

Rendering to widescreen format can be confusing. Your files can look squished even though you render in widescreen format. What's going on?

Whether 720x486 is truly widescreen or not depends on the pixel aspect ratio (in other words the shape of the pixel itself).

Years ago you likely learned that pixels are square. Well actually, they are ONLY square on the computer screen or when translated into print.

Pixels rendered for video (for a number of years now) have for the most part been rendered at a slightly different ratio(.9 for standard format). That ratio is SO CLOSE to being square that you never noticed a difference between computer screen and TV screen, even though your perfect circles and squares were just ever so slightly not perfect.

The difference? NOW with widescreen TV and monitor formats becoming more prevalent, squishing and stretching are becoming more noticeable because while the widescreen format is the same pixel dimension of the old "boxy" format (720x486), the only difference is the pixel aspect ratio has changed now to "1.21" - which is a very noticeable difference from the square, read as "1". The exception to that is true High Definition or HD formats.

So now, when you render in Lightwave and use the D1 NTSC Widescreen settings - you'll notice the pixel aspect ratio (PAR) is 1.2 (an old number and 1.21 isactually an updated PAR). So why is it squished when those files are imported it into After Effects? Why does it look squished when I play the saved movie file from the desktop?

There are a couple of wonky things going on as the computer/software industries make the transition to the new widescreen standard. in the next few years, expect things to change, but for the better. When HD is the true standard, this strange conversion will disappear.

For now, the first thing to remember, is when you view something on the computer desktop you are ALWAYS viewing it through the square pixels of the monitor. Which will cause a perfectly written file in widescreen to look squished. SO, when you intend to view a file from a computer (rather than from a DVD) then you have to compensate for this. Instructions follow.

Rendering Widescreen for Computer Screen

First make sure you are rendering in widescreen format in Lightwave.

Note the standard settings for D1 (NTSC Widescreen):

720 x 486

pixel aspect ratio = 1.2 (or you can type in 1.21)

After you import your rendered pics into After Effects, you'll notice that it reads the pixel aspect ratio incorrectly! It shows it as .9 - which is why if you create a composition using the rendered images, they look squished or don't fill the frame.

To change this incorrect perception of AfterEffects, select the image sequence and right click to reveal the menu shown to the right -- and select "Interpret Footage", then from the sub-menu, select "Main".

The Interpret Footage window will appear and since it's SO BIG, it's appearance in the image to your right has been condensed for this tutorial . . . down at the bottom of the window, you'll see 'Other Options' - select the Pixel Aspect Ratio, D1/DV NTSC Widescreen (1.2).

Once you do this, check out the corrected Pixel Aspect Ratio in the Project window of the image sequence.

The second part of this process is adjusting your render output settings to accommodate the square pixel viewing apparatus of the computer monitor.

if the display of your files still looks squished use the toggle setting to view a "corrected version" - see the image to the right.

Finally, use the following Output Module Settings to view a correctly proportioned widescreen image on the computer monitor.

In the Stretch settings, select from the drop-down menu the standard defaults for NTSC D1 Widescreen Square Pixel

When you select this, you'll see that the correct aspect ratio of the frame is 16:9 -- which is correct.

Render the file as usual. You will notice when you open it that it appears in the widescreen format it should.

Rendering Widescreen for DVD
if you plan on exporting an Mpeg2 for DVD, do the following shortened version of the above steps:

Render in D1 NTSC Widescreen in LW as usual;
Import image sequences into AE as usual;
Correct the aspect ratio of the footage in AE, so that the PAR is 1.2 - as listed above;
Lastly - render WITHOUT stretching using the usual D1 NTSC WIdescreen settings.

Why? Because TVs have naturally elongated the displayed pixels - at least until HD format!

If you play this file on a computer screen, it will look squished - but when you play this file on a TV - it will look correct.

Rendering for square pixel format (for computer screen) using Lightwave will result in a 20% longer render times because MORE pixels are being computed.

				courses	reference material
				lab information	advising information

reference materialRendering Widescreen Movies for Computer Screen & DVD
by Vonda Yarberry

Introduction Rendering to widescreen format can be confusing. Your files can look squished even though you render in widescreen format. What's going on? Whether 720x486 is truly widescreen or not depends on the pixel aspect ratio (in other words the shape of the pixel itself). Years ago you likely learned that pixels are square. Well actually, they are ONLY square on the computer screen or when translated into print. Pixels rendered for video (for a number of years now) have for the most part been rendered at a slightly different ratio(.9 for standard format). That ratio is SO CLOSE to being square that you never noticed a difference between computer screen and TV screen, even though your perfect circles and squares were just ever so slightly not perfect. The difference? NOW with widescreen TV and monitor formats becoming more prevalent, squishing and stretching are becoming more noticeable because while the widescreen format is the same pixel dimension of the old "boxy" format (720x486), the only difference is the pixel aspect ratio has changed now to "1.21" - which is a very noticeable difference from the square, read as "1". The exception to that is true High Definition or HD formats. So now, when you render in Lightwave and use the D1 NTSC Widescreen settings - you'll notice the pixel aspect ratio (PAR) is 1.2 (an old number and 1.21 isactually an updated PAR). So why is it squished when those files are imported it into After Effects? Why does it look squished when I play the saved movie file from the desktop? There are a couple of wonky things going on as the computer/software industries make the transition to the new widescreen standard. in the next few years, expect things to change, but for the better. When HD is the true standard, this strange conversion will disappear. For now, the first thing to remember, is when you view something on the computer desktop you are ALWAYS viewing it through the square pixels of the monitor. Which will cause a perfectly written file in widescreen to look squished. SO, when you intend to view a file from a computer (rather than from a DVD) then you have to compensate for this. Instructions follow.
Rendering Widescreen for Computer Screen First make sure you are rendering in widescreen format in Lightwave. Note the standard settings for D1 (NTSC Widescreen): 720 x 486 pixel aspect ratio = 1.2 (or you can type in 1.21)

After you import your rendered pics into After Effects, you'll notice that it reads the pixel aspect ratio incorrectly! It shows it as .9 - which is why if you create a composition using the rendered images, they look squished or don't fill the frame.

To change this incorrect perception of AfterEffects, select the image sequence and right click to reveal the menu shown to the right -- and select "Interpret Footage", then from the sub-menu, select "Main".

The Interpret Footage window will appear and since it's SO BIG, it's appearance in the image to your right has been condensed for this tutorial . . . down at the bottom of the window, you'll see 'Other Options' - select the Pixel Aspect Ratio, D1/DV NTSC Widescreen (1.2).

Once you do this, check out the corrected Pixel Aspect Ratio in the Project window of the image sequence. The second part of this process is adjusting your render output settings to accommodate the square pixel viewing apparatus of the computer monitor.

if the display of your files still looks squished use the toggle setting to view a "corrected version" - see the image to the right.


Finally, use the following Output Module Settings to view a correctly proportioned widescreen image on the computer monitor. In the Stretch settings, select from the drop-down menu the standard defaults for NTSC D1 Widescreen Square Pixel When you select this, you'll see that the correct aspect ratio of the frame is 16:9 -- which is correct. Render the file as usual. You will notice when you open it that it appears in the widescreen format it should.

Rendering Widescreen for DVD if you plan on exporting an Mpeg2 for DVD, do the following shortened version of the above steps: Render in D1 NTSC Widescreen in LW as usual; Import image sequences into AE as usual; Correct the aspect ratio of the footage in AE, so that the PAR is 1.2 - as listed above; Lastly - render WITHOUT stretching using the usual D1 NTSC WIdescreen settings. Why? Because TVs have naturally elongated the displayed pixels - at least until HD format! If you play this file on a computer screen, it will look squished - but when you play this file on a TV - it will look correct. Rendering for square pixel format (for computer screen) using Lightwave will result in a 20% longer render times because MORE pixels are being computed.