pixel aspect ratio again at DVinfo.net

Colin Sze · February 14th, 2004, 11:15 AM

I capture two D1 PAL footage at 720 x 560 frame ratio (1.067 pixel aspect), what is the correct pixel count if I am going to insert a still image from a digicam which comes with square pixel. I tried 720 x 540 to maintain a 4:3 frame, but on preview monitor it is black framed.

Julian Luttrell · February 14th, 2004, 11:36 AM

It depends how you are inserting the image. What NLE are you using?

A 768 x 576 square pixel image is exactly 4:3 in aspect - so if you create an image in Photoshop, this is the size to use.

I always fix the still image before importing it into my NLE - just adjust the image size in Photoshop to 720x576 (do not kepp the aspect ratio!) first (it will look squashed from side to side).

This way you aren't relying on the NLE to do maintain any aspect ratios...

Julian

Bryan McCullough · February 14th, 2004, 12:06 PM

For what it's worth, Photoshop CS now does non-square pixles.

It's been real helpful.

Colin Sze · February 14th, 2004, 12:36 PM

Thanks Julian and Byran. Now I get it done.
I made a typo mistake in my thread; the D1 PAL resolution should be 720 x 576.
For anyone who cares, this is what I found:
I should not have sticked to 720 and divided it by 1.33 to get 540 (height), instead, you should time 576 by 1.33 to get 768 (width). That explains why my still does not fill the frame properly. I tried what Julian suggested to get a squeezed image (from 768 x 576 to 720 x 576) and bring it to Premere Pro. Suprisingly, this NLE correctly interprets the image as 1.067 pixel though I have not told it such. I also tried bringing an un-squashed still image at 768 x 576 to NLE, this time NLE interperts it as square pixel. Amazing .... both ways work fine !!
Byran, I do not know Photoshop CS works with non-square pixel. Mine is Photoshop 6.

Rob Lohman · February 15th, 2004, 04:42 PM

Both ways should work in an NLE (720x540 or 768x576). BUT,
you should always go with the larger resolution so you don't
loose resolution. So yes, 768x576 is the size to use. NOT
720x576 (because the paintprogram cannot do pixel aspect
conversion and you will loose resolution if PPro has to do it with
only 720 pixels) or 720x540.

February 14th, 2004, 11:15 AM	#1
Colin Sze Regular Crew Join Date: Dec 2003 Location: Hong Kong Posts: 32	pixel aspect ratio again I capture two D1 PAL footage at 720 x 560 frame ratio (1.067 pixel aspect), what is the correct pixel count if I am going to insert a still image from a digicam which comes with square pixel. I tried 720 x 540 to maintain a 4:3 frame, but on preview monitor it is black framed.

February 15th, 2004, 04:42 PM	#5
Rob Lohman RED Code Chef Join Date: Oct 2001 Location: Holland Posts: 12,514	Both ways should work in an NLE (720x540 or 768x576). BUT, you should always go with the larger resolution so you don't loose resolution. So yes, 768x576 is the size to use. NOT 720x576 (because the paintprogram cannot do pixel aspect conversion and you will loose resolution if PPro has to do it with only 720 pixels) or 720x540. __________________ Rob Lohman, visuar@iname.com DV Info Wrangler & RED Code Chef Join the DV Challenge \| Lady X Search DVinfo.net for quick answers \| Buy from the best: DVinfo.net sponsors

February 14th, 2004, 11:36 AM	#2
Julian Luttrell Regular Crew Join Date: Oct 2002 Location: Cambridge, UK Posts: 164	It depends how you are inserting the image. What NLE are you using? A 768 x 576 square pixel image is exactly 4:3 in aspect - so if you create an image in Photoshop, this is the size to use. I always fix the still image before importing it into my NLE - just adjust the image size in Photoshop to 720x576 (do not kepp the aspect ratio!) first (it will look squashed from side to side). This way you aren't relying on the NLE to do maintain any aspect ratios... Julian

February 14th, 2004, 12:06 PM	#3
Bryan McCullough Major Player Join Date: Oct 2003 Location: Richardson, TX Posts: 842	For what it's worth, Photoshop CS now does non-square pixles. It's been real helpful.

February 14th, 2004, 12:36 PM	#4
Colin Sze Regular Crew Join Date: Dec 2003 Location: Hong Kong Posts: 32	Thanks Julian and Byran. Now I get it done. I made a typo mistake in my thread; the D1 PAL resolution should be 720 x 576. For anyone who cares, this is what I found: I should not have sticked to 720 and divided it by 1.33 to get 540 (height), instead, you should time 576 by 1.33 to get 768 (width). That explains why my still does not fill the frame properly. I tried what Julian suggested to get a squeezed image (from 768 x 576 to 720 x 576) and bring it to Premere Pro. Suprisingly, this NLE correctly interprets the image as 1.067 pixel though I have not told it such. I also tried bringing an un-squashed still image at 768 x 576 to NLE, this time NLE interperts it as square pixel. Amazing .... both ways work fine !! Byran, I do not know Photoshop CS works with non-square pixel. Mine is Photoshop 6.