Desktop Video/Graphic/Video ratios

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Question
QUESTION: I am making a Video NTSC 4:3 DV 720x480 and I want to put a Graphic infront of it and I want it to cover the whole Video.

So do I make my Graphic 655x480 Pixals?

ANSWER: Bob,

What software are you going to create the graphic in? What editorial software are you using.

These two are critical questions.

(The square pixel adjustment for 720x480 is 640x480.)

---------- FOLLOW-UP ----------

QUESTION: I am useing Corel PhotoPaint and I know that Graphic Images use Sqware Pixals and Video uses None Sqware Pixals.

So if I want my Graphic to cover all of my 4:3 NTSC Video I thought I make it 655x480 am I off?

Answer
Bob,

The reason I asked you the software is that Adobe Photoshop has had the ability to handle nonsquare pixels for a decade (since Adobe Photoshop CS.)

The reason I asked which editing tool is because some of them handle this fine and some had different problems.

Here's the short answer: 640 x 480. (Or 720 x 540. But 640 x 480 is probably cleaner.)

Here's the longer answer:
There are actually two sizes that a still can be to accomodate NTSC/DV of 720 x 480. (There is another sizing for NTSC, known as NTSC 601, which is 720 x 486 pixels.) For 4:3 ratio, the size conversion is .9.

So, 720 x 480 can become 720 x 540 (where you convert based on the height) or 640 x 480 (where you convert based on the width.

Both are correct. But interlaced images (the process of storing a frame in alternating fields due to the redraw of the raster of television) means that vertical distortion is a bit more likely to cause problems due to their temporal difference between fields and expanding vertically leaving some pixels not hitting the field pair fully.

Even longer answer:
http://lurkertech.com/lg/pixelaspect/

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Jeff Greenberg

Expertise

I can answer questions about Final Cut, Avid, DV cameras + editing, Hi-def, production, filmmaking, DVD creation and special effects. Please do not ask me questions about your desktop, NOR your windows machine, nor ANYTHING to do with copyright infringement.

Experience

I'm a film editor and certified trainer for about ten different applications.

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videography

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BA, Penn State university in film.

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