Aspect Ratio

[bubba]

I see I don't have to use the pre-canned resolutions in the render tab. I can set my own. So I am wondering how to compute the proper aspect ratio?

[robcat2075]

for example... to make a 16:9 rectangle that would play as 480p on Youtube...

 

 

multiply 480 (vertical resolution) x 16 and divide by 9 to get the horizontal res. About 854

 

 

so you'd render to 854x 480 pixels

[bubba]

But I was thinking more for the render settings. For example you can set to render 1024x768 or 1280x960, but then what do you set the Aspect Ratio to - .75, 1 ?

[robcat2075]

The actual "aspect ratio" parameter was to work with pixels that are not square.

 

For example 640x480 would equal the 4x3 shape of old TV but they packed a bit more horizontal res into it by using about a .9 aspect ratio to make the pixels slightly skinny and rendered with 720x 480 pixels.

 

Unless you are trying to do something for digital NTSC leave your aspect ratio at 1.0. As far as I know all modern HDTV uses square pixels.

[largento]

It's really not very complicated.

 

I've only used it for NTSC DVDs. DVDs store images at 720x480 pixels. This is neither a 4:3 or a 16:9 aspect ratio.

 

Here's a quick graphic I put together. It's 720x480 pixels. The black bar is 16:9 and the red box is 4:3, as you can see, an adjustment is necessary for both types of video.

 

 

In order to get your image to appear in the correct aspect ratio (i.e. not squished or stretched), you need to adjust the aspect ratio to account for the pixels. Widescreen has wider pixels (1.21 aspect ratio) and standard has thinner pixels (.91 aspect ratio.)

 

If you are creating something for the web or a Blu-Ray, you don't have to bother with this, because they use square pixels.

[bubba]

Whoa! instead of being simple, I am getting more confused. Right now I am trying to increase the size of my renders. My monitor is 1900 X1200 so 640X480 is quite small. 1024X768 is a nice size for trial viewings and I think that is still 4:3 ratio, so the aspect ratio is .9?

[robcat2075]

If you are going to just view something on your monitor, stick with square pixels, because the monitor has square pixels.

 

1900x1200 is not a 4:3 ratio but that almost certainly isn't framed in a 4:3 area rectangle. If you measured it you'd find it to be about 1.58 to 1

 

You can render at 1024x768 but that will take longer than 640x480.

 

If you want to see a 640x480 movie larger, the easiest thing to do is full screen the player or use Quicktime's View>Present Movie option.