Export 16x9 Anamorphic for Computer: Correct Numbers?

[Michael D. Shivers]

Hello all,

I have read through the forums trying to figure out the possible answers to this and I haven't found the exact answer. I have a few questions about exporting 16x9 anamorphic clips for web/computer viewing. Shooting on a XL2, editing with FC studio.
I know that anamorphic footage is 720x480 and its anamorphically squeezed in FCP or QT.
If i want to export the footage for computer with no black bars, etc- just 16x9.
i have read earlier that 854x480 is the correct largest version. But doing the math its a bit off (53.375 x53.333)
So then I saw another post his footage looked great and it was 720x405

So is there any list on any website or someone so kind to write out a few of the breakdowns for exporting 16x9? What is the first real number that i start off with to convert? 960x480?
If so the first could be x / 1.25 =768x384
Is this right?

example for 4x3 and what i am looking for in 16x9 is:
640x480 (because i am starting off with 720x480)
512x384
320x240


this may be a bit confusing, let me know if I can clairfy!

thanks
Michael

[Boyd Ostroff]

Hey, it ain't rocket science here! :-)

Since computer monitors have square pixels, 16:9 means exactly that - divide 16 by 9 and you get the correct proportion. So first you need to pick either the width or the height of your final product. If you want an image that's 480 pixels high then the width would be 480 x 16 / 9 = 853.33. Since you can't have a fraction of a pixel you could either round up to 854 or down to 853, but most people seem to favor even numbers for this sort of thing. That would make the final image 854x480. Substitute any other number you want for the height and calculate the width the same way.

If you prefer to start with a known width then it's equally simple. If you want the image to be 720 pixels wide then the calculation is 720 x 9 / 16 = 405. That would give you a 720x405 final size.

It's just simple proportions, nothing mysterious. Those other sizes you gave -- 640x480, 512x384 and 320x240 -- have nothing to do with 16:9. They are all 4:3 images. Do the same thing to figure these out, eg:

(height) x 4 / 3 = width
(width) x 3 / 4 = height

But for 16:9 it's:

(height) x 16 / 9 = width
(width) x 9 / 16 = height

Got it? There will be a quiz in the morning, so you'd better review your notes ;-)

[Dave Perry]

I use 854x480 for full size and 428x240 for web movies.

[Michael D. Shivers]

Aswsome. You guys are great. I think I was confused with the anamorphic aspect of it. Since capturing it was 720x480, i didn't know how that translated to 16x9 when exporting for computer.

Your easy formula explains it to me. Math was never a strong subject for me!!

Another question- but I may need to post another topic, but when using Compressor, there are settings to tell what Frame size of output you want. Right below those settings are a few drop down buttons:
Pixel Aspect:
Constrain to display aspect:

1. Pixel Aspect: Do I need to adjust those at all for anamorphic, or square (pixel aspect)

2. Constrain to display aspect: putting 16x9?

Or just leave it alone since defining my frame size as 854x480 (or whatever correct 16x9 size)?

I know some of you avoid compressor like the plague, but if you do use it, your info would be great.

thanks again
michael


http://www.mdshivers.com