720x480 Square-Pixel Image Sequence?
by Brittnell Anderson
on
Jun 11, 2008 at 10:53:24 pm
Is it possible to render out an image sequence (say .tga) that is 720x480 / square pixel aspect ratio (1.0)?
My experience is that outputting video files work fine, but image sequences rendered at 720x480 (also 720x486) seem to automatically switch to .9 pixel aspect no matter what.
Re: 720x480 Square-Pixel Image Sequence? by Dave LaRonde on Jun 11, 2008 at 10:56:16 pm
If all you use are the AE DV or D1 comp presets, you'll have trouble. But it you make a CUSTOM comp, you can make it in any size and pixel aspect ratio that you wish. Give it a try.
Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA
Re: 720x480 Square-Pixel Image Sequence? by Brittnell Anderson on Jun 11, 2008 at 11:02:25 pm
Yeah, this is using "custom" settings.
720x480
Square Pixels
30fps
Images used in the comp are also 720x480 Square Pixel .tgas (rendered out of 3DS Max).
Render settings are the same, with no stretching, scaling, or anything else. I just can't get it to write out anything but .9 pixel aspect for these image sizes... interestingly, making the comp 720x481 makes it render correctly (square pixels).
Re: 720x480 Square-Pixel Image Sequence? by Darby Edelen on Jun 11, 2008 at 11:54:02 pm
[Brittnell Anderson]"Render settings are the same, with no stretching, scaling, or anything else. I just can't get it to write out anything but .9 pixel aspect for these image sizes... interestingly, making the comp 720x481 makes it render correctly (square pixels)."
The pixel aspect ratio is irrelevant in this situation. If you want them to be seen as square pixel in Photoshop I suppose you could record an action that changes them from 0.9 PAR preview to Square Pixel, but this doesn't change what the pixels are, only the way they are seen in Photoshop.
If you're complaining about them being interpreted as 0.9 on import into AE, then just Reinterpret the footage to be square pixel (cmd-f or ctrl-f on PC). AE has a list of interpretation rules that says "If an image is 720x480 it is probably NTSC and should be interpreted with a 0.9 pixel aspect ratio." You can override this after import.
Darby Edelen Lead Designer Left Coast Digital Santa Cruz, CA
Re: 720x480 Square-Pixel Image Sequence? by Brittnell Anderson on Jun 12, 2008 at 12:41:14 am
Yeah, that all makes sense.
We were actually running into this issue when bringing the AE comp output into a Premiere project, where the majority of footage was straight out of 3DS Max (@ 720x480 1.0) and the project settings to match (720x480 1.0).
I didn't think to have my editor turn off Premiere's "use image pixel aspect" for these files. Works, but still kind of strange that these products assume that what you set your output at is not really what you want.
Re: 720x480 Square-Pixel Image Sequence? by Dave LaRonde on Jun 12, 2008 at 12:01:43 am
[Brittnell Anderson]"I just can't get it to write out anything but .9 pixel aspect for these image sizes... "
What are you using to look at the file rendered from AE? A media player, an editing application, a different media application?
I THINK (I'm not sure) that Apple has given the quicktime player some semi-intelligence, so that it attempts to put 720x480 into a 4x3 ratio... could that be the cause?
And let's make certain that I've got your problem straight: at 720x480 square pixels in AE, your screen aspect ratio is lightly wider than 4x3, but circles in the picture look perfectly circular. However, after you render out of AE and view it, the image looks just about 4x3, but those circles have become ovals that have been squeezed horizontally.
Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA
Re: 720x480 Square-Pixel Image Sequence? by Steve Roberts on Jun 12, 2008 at 1:03:31 pm
Why choose 720x480 square pix in the first place?
I ask this because, if you want to go to DVD, and MAX only renders square pixels, you should have made the MAX camera 720x540 for 4:3, or 864x486 for 16:9. 720x480 square pix is between those two: neither fish nor fowl.
So. Why choose 720x480 square pix (in MAX) in the first place?
Re: 720x480 Square-Pixel Image Sequence? by Nate Hanson on Jun 12, 2008 at 4:49:34 pm
Sorry to butt in on this conversation...butt...
I always have to send my AE stuff out with the "Stretch" check box checked, and I have to change the dimensions to 740x534 (instead of 740x480). I found that number in a help file.
If I don't do that, my stuff looks stretched after I bring it in to Final Cut Pro and then export my finished product at 720x480. I don't understand why.
Nate*
* Author has no real-world experience; he works in the plastic-bubble world called "Public Education".
