1440 vs 1920 at DVinfo.net

Chris Gerow · March 4th, 2007, 12:11 PM

Hi,
I have read a number of post about 1440 and 1920 resolution in this forum - Good reading BTW. I went to my neighborhood camera store and shot a clip using the Canon A1 (to tape) and transfered it to my laptop. All is well so far.

I have read in the manual that it records as 1440. When I bring the clip into PP and it too shows as 1440. However, here is where I'm getting confused - when I play it on windows medial player, PP or VLC - it has a 16:9 aspect ratio.

What gives? Is play back really 1920?

If so, How does it add the extra pixels?

Many thanks to you all - this has been very informative.

Thanks,
ChrisG

Marlon Torres · March 4th, 2007, 12:43 PM

Set pixel aspect ratio to 1.333

Chris Gerow · March 4th, 2007, 02:20 PM

Quote:

Originally Posted by Marlon Torres

Set pixel aspect ratio to 1.333

Marlon,
I like the idea of 1920, but, what is the price - I must be loosing something in resolution - correct?

This issues seems to be with the V1 also.

ChrisG

Alan James · March 4th, 2007, 02:30 PM

HDV stores data as 1440X1080 then stretches it back into 16X9. SDV works the same way; storing data in 720X480 and stretching it back. Same with DVDs and so on. You end up loosing a lot of horizontal detail. The biggest problem I have found is with the FX1 and the Z1 (although I’m sure other cameras have it too). Both those cameras chips are actually 960X1080, so they only have half the resolution of square pixel HD. They also pack that signal into 1440 lines (making it worse) then your NLE stretches it back out to 16X9 (making it more worse). Until I see really good prosumer HD that’s not as compressed I’m gunna keep shooting progressive SD. I'm actually liking the sound of the GY-HD250 but havnt used it so I can't speak for it, but still compression for visual effects is a pain. Hope that helps you out.

Chris Gerow · March 5th, 2007, 09:37 AM

I finally found out what is going on here. Again – thanks to the internet.

There is a difference between a SAR and a PAR. PAR is a pixel aspect ration and as you would guess, measures the number of pixels. A SAR is a screen aspect ratio which in my case is 16:9. If the PAR is 1440x1080 – this equals a SAR of 1920x1080 because the pixels on a screen are not square – they are rectangular.

Now this is the part that I had some much problem with. If a screen has 1080 lines and the aspect ratio is 16x9, then the math works out to 1920. So, 1920 is not a count of pixels which was my mistake – is a count of units (what ever that means).

This is important for me because if I render something in Premiere Pro that is 1920x1080 - this is a SAR figure – the results will actually be 1440x1080 pixels. This was driving me bats.

Now, I’m a newbie at this stuff – You experts – is this all correct?

Thanks,
ChrisG

Tom Roper · March 5th, 2007, 10:15 AM

You're going to render the project at 1440x1080, 16x9.

The playback device, pc, mac, cam, media streamer or HD-DVD player will handle the rescaling to 1920x1080

March 4th, 2007, 12:11 PM	#1
Chris Gerow New Boot Join Date: Feb 2007 Location: Leesburg, Va Posts: 11	1440 vs 1920 Hi, I have read a number of post about 1440 and 1920 resolution in this forum - Good reading BTW. I went to my neighborhood camera store and shot a clip using the Canon A1 (to tape) and transfered it to my laptop. All is well so far. I have read in the manual that it records as 1440. When I bring the clip into PP and it too shows as 1440. However, here is where I'm getting confused - when I play it on windows medial player, PP or VLC - it has a 16:9 aspect ratio. What gives? Is play back really 1920? If so, How does it add the extra pixels? Many thanks to you all - this has been very informative. Thanks, ChrisG

March 4th, 2007, 12:43 PM	#2
Marlon Torres Major Player Join Date: Apr 2005 Posts: 230	Set pixel aspect ratio to 1.333

March 4th, 2007, 02:30 PM	#4
Alan James Regular Crew Join Date: Jul 2006 Location: Tampa, Florida Posts: 261	HDV stores data as 1440X1080 then stretches it back into 16X9. SDV works the same way; storing data in 720X480 and stretching it back. Same with DVDs and so on. You end up loosing a lot of horizontal detail. The biggest problem I have found is with the FX1 and the Z1 (although I’m sure other cameras have it too). Both those cameras chips are actually 960X1080, so they only have half the resolution of square pixel HD. They also pack that signal into 1440 lines (making it worse) then your NLE stretches it back out to 16X9 (making it more worse). Until I see really good prosumer HD that’s not as compressed I’m gunna keep shooting progressive SD. I'm actually liking the sound of the GY-HD250 but havnt used it so I can't speak for it, but still compression for visual effects is a pain. Hope that helps you out.

March 5th, 2007, 09:37 AM	#5
Chris Gerow New Boot Join Date: Feb 2007 Location: Leesburg, Va Posts: 11	I finally found out what is going on here. Again – thanks to the internet. There is a difference between a SAR and a PAR. PAR is a pixel aspect ration and as you would guess, measures the number of pixels. A SAR is a screen aspect ratio which in my case is 16:9. If the PAR is 1440x1080 – this equals a SAR of 1920x1080 because the pixels on a screen are not square – they are rectangular. Now this is the part that I had some much problem with. If a screen has 1080 lines and the aspect ratio is 16x9, then the math works out to 1920. So, 1920 is not a count of pixels which was my mistake – is a count of units (what ever that means). This is important for me because if I render something in Premiere Pro that is 1920x1080 - this is a SAR figure – the results will actually be 1440x1080 pixels. This was driving me bats. Now, I’m a newbie at this stuff – You experts – is this all correct? Thanks, ChrisG

March 5th, 2007, 10:15 AM	#6
Tom Roper Trustee Join Date: Jun 2004 Location: Denver, Colorado Posts: 1,891	You're going to render the project at 1440x1080, 16x9. The playback device, pc, mac, cam, media streamer or HD-DVD player will handle the rescaling to 1920x1080