Pixel Aspect Ratio MADNESS

[Steve Roberts]

Your Photoshop images should be 720×540 square pixels, or 720×480 non-square-pixel (.9). Don’t mix those up.

If the 720×540 has a few pixels out of frame, don’t worry about those — let them go out of frame. (it’s because DV has had a few pixels lopped off its frame size — long story)

Either size I listed above will be appropriately adjusted in the AE comp.

[Steve Roberts]

Ah. I was assuming that you wanted your images to fill the frame.

If you don’t want that, then go ahead and make them any size and pixel aspect ratio you want — AE will make them look right.

[Brendan Coots]

Yeah, a lot of the PAR confusion comes into play when people design their graphics at the actual dimensions of the video. AE assumes any source material (stills included) that is 720×480 (or other standard broadcast sizes), is a video source and not square pixel, so it will try to apply aspect correction.

The easiest way around this is to always design your images a little bigger, maybe by 5 pixels all around, so that AE will leave them square pixel and everything works intuitively.

Brendan Coots
Splitvision Digital
http://www.splitvisiondigital.com

[Steve Roberts]

[Brendan Coots] “The easiest way around this is to always design your images a little bigger, maybe by 5 pixels all around, so that AE will leave them square pixel and everything works intuitively.
“

Sorry, no, if you’re working in 4:3 NTSC, and you want your square-pixel Photoshop images to fill the frame, they should be a multiple of 4×3: 720×540 or 648×486.

If you take 720×480 and add a few pixels to make them (for example) 725×485, yes, they will be interpreted by AE as square pixel, but they will be too wide for the 4:3 frame shape, giving you space at the top and bottom. Use 720×540 or 648×486.

(For widescreen, the screen in square pixels is a multiple of 16×9: 864×486.)

Search the COW for Rick Gerard’s “Pixel Madness” or “Dr. Strangepixel” tutorial for more.

[Brendan Coots]

? If I drop a 723×483 image into a 720×480 comp, the excess 3 pixels are cropped off on all edges, and I am left with a perfectly centered, edge-to-edge file. Sure, if you want to scale the file to fit EXACTLY this wouldn’t be the best way, but you wouldn’t need to scale it down since you are only adding a few pixels – the extra pixels are just hanging outside of the viewer.

Brendan Coots
Splitvision Digital
http://www.splitvisiondigital.com

[Steve Roberts]

Note: i am assuming that the original poster is using square pixels in Photoshop for his images.

A 723×483 square-pixel image would indeed fit into a 720×480 square-pixel comp as you say.

However, I ask you to name the number of times that a 720×480 square-pixel comp would be used. As you know, 720×480 is only used in a non-square pixel context, with a PAR of .9, or more correctly, 10/11.

Consider this: a correct square-pixel comp for 4:3 TV is 640×480, 648×486 or 720×540. All those are multiples of 4×3. However, 720×480, square-pixel, is not a multiple of 4×3 — it is more like 4.5×3, which is too long.

So a 720×480 square-pixel image would not fill a DV (720×480, non-square PAR) comp, even if a few pixels were added, because it would be too long. All square-pixel images, to fill a 4×3 comp, must have dimensions that are a multiple of 4×3, at least 640×480 for DV, and 648×486 for D1.

[Jojo Galan]

Hello,

I am working in Adobe After Effects CS5.
I have a video file recorded in a DVX100B:

according to after effects the video has specs of:
720×480 (0.91) separating (lower)
23.976 fps 3:2 removal (https://WWWSW) – 24p Advance

What is the best timeline/composition to edit in?
I am currently using a DV Timeline 720 x 480 – 3:2

Why do I have to use a square pixel aspect ratio on the timeline for the video to look right on export. Why can’t I use a DV aspect ratio?

Thanks

[Steve Roberts]

Yes. Import the video clip and drag it onto the New Composition button at the bottom of the Project window. The comp will be right.

The movie that you render will look right on TVs and DVDs but too wide when viewed on a computer. If you want the final product to be viewed on a computer (internet, flash, quicktime, etc.), you need to re-render the final movie to one of those 4:3 square pixel sizes such as 640×480, 320×240, whatever.

[Jojo Galan]

Thank You Steve for being considerate and patient.

When you say TV, does that mean RCA inputs, or older TV? Because I look at the video through the HDMI on my TV and it still looks stretched.

[Zeke Meginsky]

Hi, Steve. I saw this thread while looking up Pixel Aspect Ratio in Google. You seem like you know what you’re talking about. This PAR stuff is driving me crazy. I just want to make sure my pictures look as proportionate as possible (and sometimes it’s hard to tell).

So if I have a big picture that is in square pixels and was taken with a normal digital camera, what should I do with it? If I want it to fill the screen (NTSC DV), I should make it 720×540, not 720×480? That is where I’ve gotten confused. Because some people say to make it to 720×480..

And if I want to do any zooming or panning on it, then After Affects will take care of it as long as I specify that it was originally square pixeled?