PAL D1/DV Widescreen square pixel settings in After Effects (CS4 vs CS3)
Seems the latest version of After Effects from Adobe (CS4) has changed the PAL D1/DV Widescreen square pixel preset.
In CS3, compositions using that preset would be set to 1024 x 576 pixels. The new version (CS4) uses 1050 x 576.
So which is right? 1024 or 1050?
Well, to begin with, it’s all a bit complicated. I can still remember when it was first explained to me many years ago when I was still at the BBC, and it’s the kind of thing that’s quite difficult to get your head around without drawing little pictures on the back of envelopes. Anyway, there’s a few resources out there that try to explain this (links included below) – but I thought I’d have a go myself.
Oh, and before we get too bogged down, I’m talking about standard definition PAL here. The following explanation assumes 576 visible TV lines (out of the total of 625). So when I talk about aspect ratios and pixel dimensions the vertical height is always 576 regardless.
OK, here we go.
TV pixels aren’t square
A square pixel device (like a computer) would need an image to be 768×576 to maintain a 4×3 aspect ratio.
But TV pixels are rectangular – instead of 1×1, they’re more like 1×1.094.
So if we rewind a bit to the old analogue days – you can see from the diagram below that our TV set with its wider pixels is effectively only 702 pixels across.
television pixels aren't square
Here’s the crucial part – digital TV pictures are wider
The key to all this to remember that digital TV pictures are wider than analogue.
Digital TV pictures are 720 pixels wide.
But the 4×3 image (702 pixels wide) sits inside those 720 pixels.
There’s an extra 9 pixels each side.
digital TV pictures are wider than analogue - the 4x3 bit sits inside
The BBC guide to picture sizes says that these extra pixels are ‘required for digital processing’.
But, they might show up as black strips each side if the whole image is shrunk down via a DVE, or maybe these days if you are running your video in a window on a computer screen. I know that converting a 1024-wide movie from a Quicktime .mov to .mp4 format using Mpeg Streamclip does introduce black lines each side. Or at least it did for me the other day.
So if you’ve ever wondered ‘Why has my video got black strips each side?’ – this is probably why.
The reason for making your original After Effects composition wider is to guarantee that the whole image is filled with picture information. This will avoid either getting black lines each side, or having the application stretch the source material to fit, ending up with an image that’s ever so slightly distorted.
Adjustment for 4×3 compositions
For a 4×3 image that means your computer (square pixel) version would need to be 788 pixels wide.
Notice we now have allowed 10 extra (square) pixels each side on our source image. These equate to the 9 pixels (non-square) TV pixels we need.
To fill the entire (4x3) image area, build at 788 pixels wide
And the same is true for 16×9 widescreen images too.
16×9 widescreen adjustment
Remember that your original 16×9 image (1024×576 pixels) is only going to occupy the middle part of the TV screen. You still need to account for those extra pixels each side. Again, taking into account that the TV pixels aren’t square, this time we’ll need 13 (square) pixels on our source material to fill in the missing areas.
Widescreen composition should be 1050 pixels wide
So your original (square pixel) After Effects compostion needs to be 1024+13+13 pixels wide. Namely, 1050×576 to guarantee that it maps correctly on to the 720×576 digital output.
I don’t know whether Adobe, or makers of other applications were doing something clever behind the scenes to compensate in AE CS3 for 1024px projects to eliminate black edges. I suspect that what was really happening is that the end results when viewed on a real TV were just stretched very slightly, or any missing picture was hidden by overscan.
Anyway, it looks like Adobe have decided to use 1050 from now on.
And to be fair, nearly everyone I knew at the BBC was working to 1024. A few geeky designers like me tried to keep the 1050 flag flying, but as you can see, it’s not really the sort of thing anyone wants to keep explaining, especially if (like me) you don’t really understand it all in the first place.
Anyway. I hope that’s helped.
But, one last thing. I can remember MANY years ago doing a test at the BBC. I prepared two Photoshop images, each with a perfect circle in the centre of the screen. One was 1024 wide, the other 1050 wide. I scaled them both to 720 and laid them both off digitally and viewed them both on our broadcast-quality monitors. The 1050 one looked perfect, and the 1024 one looked very slightly distorted. Which is why I used 1050 for the BBC Weather animations a few years ago which featured a big glass circle fairly prominently.
Please feel free to comment here if you have anything useful to add. Worthwhile comments are ‘no-follow’-free!
Much love,
Mike
March 6th, 2009 at 9:02 pm
This is a great post. I encourage you to leave a comment on the page of After Effects Help that you link to above, linking back to this post. If you do, it’ll remind me to work the link into the main body of the document the next time that I update After Effects Help on the Web.
March 27th, 2009 at 8:31 pm
[...] After Effects CS4 – pixel aspect ratios – 1024 vs 1050 | Mike … [...]
March 31st, 2009 at 12:17 pm
Thanks for this, if Adobe have decided to make this change then why has photoshop not been updated with the new aspect ratios – it makes it very confusing as designers are designing to one standard and AE editors to another – come on Adobe sort it out.
April 20th, 2009 at 12:36 pm
I’ve been doing it wrong all these years! Great explaination. It’s seem that everyone is confussed about aspect ratios.
As 1050×576 isn’t 16:9 and Photoshop CS4 presets are still 1024×576 from a design point of view do I need to think about the extra 26 pixels? It seems to me that it’s just dead space that never gets seen?
April 21st, 2009 at 2:58 am
After many years we used to use 768×576 (wide and standard) they “discover” and illuminate us! Adobe, please allow us to make our own presets especially with our own aspect ratio!
April 27th, 2009 at 11:06 pm
Thanks Mike.
One note: I believe that your diagram entitled “television pixels aren’t square” is incorrect. Aren’t non-square TV pixels longer on the vertical side? You have the pixels looking wider in your diagram.
A video frame looks a bit too wide when viewing it on a PC, but when viewing it on a TV it skinnies up, therefore it seems as though the TV pixel would be taller.
I’m no expert, so can you tell me if this is correct?
Thanks!
Jim
April 27th, 2009 at 11:51 pm
Jim,
Thanks for the comment.
Possibly a PAL vs NTSC thing? I have a hunch NTSC footage gets squashed/stretched the other way from PAL.
Just checked – Adobe give pixel aspect ratios of 0.91 for D1/DV NTSC and 1.09 for D1/DV PAL.
Might that be it?
Mike
April 28th, 2009 at 12:56 am
That sounds like it’d be it! SO a PAL pixel is WIDE, whereas an NTSC pixel is TALL!
Learn something new every day…
Thanks!
Jim
June 22nd, 2009 at 5:22 pm
Thanks for the explanation; the BBC “Commissioning – A Guide to Picture Size” web page also confirms that many of us have been doing it wrong for a long time.
But this begs the question – does this mean that the 1920×1080 square pixels for HDTV is also wrong by 18 pixels?
Jeff
July 8th, 2009 at 12:27 pm
It is a real shame that it is now so complicated, as 1050 x 576 square pixels does not have an aspect ration of 16:9 !
Boaz
August 18th, 2009 at 11:39 am
Thanks for this post – very well explained. cheers, Axel
August 25th, 2009 at 4:13 am
[...] Afford has put together a good explanation on his website. Mike used to work for the BBC, but to get a direct statement from the BBC, you should check out [...]
August 25th, 2009 at 10:17 am
Very useful post, thank you.
September 19th, 2009 at 10:41 pm
I’m not sure my problem qualifies as a “square pixel”. Once or twice a week I have 1, 2 or 3 black rectangles about 1″ wide and 1 1/2″ tall. I have a 37″ 2 year old LCD Vizio TV. Any suggestions?
December 16th, 2009 at 10:26 am
Hi Mike,
Thanks a lot for taking the time to explain this! I just switched to CS4 and the new sizes were driving me crazy to say the least. Now i know why wich will make me sleep a lot better.
So again thanks for this!!
Kind regards,
Eddie
NL
January 19th, 2010 at 12:12 pm
Hi Mike,
We just switched back from Adobe Premiere CS4 to Avid Media Composer again. When still working With Premiere, we worked with “1050″ as it was compatible with After Effects CS4. (It all made sense when I first heard about it and now even more with your post…).
I’m curious though, how many other editing suites work with “1050″? I know Avid doesn’t… Will it be an industry standard or does the flatscreen (HD) TV-market have anything to do with it? We Use PS CS4 and AE CS4 and Avid. I guess we just have to work with
“1024″ again… What would you recommend?
Grtz,
Owen
January 30th, 2010 at 5:28 pm
Hi Owen,
I tend to build everything using 1050 now, but you’re right, some editing suites really don’t know what to make of it. (I came across the Avid issue while still at the BBC – but don’t know of others of the top of my head).
I would hope 1050 becomes industry standard eventually as it does lead to the best (i.e. non-distorted) results.
My suggestion is still to build at 1050 in After Effects (and thus any Photoshop material also at 1050) – that way you still have the option of dropping the whole thing into a new 1024 comp before the final render. It’s a bit of a cop out, but at least then if you need the extra pixels, you have them.
Or render at 1050 and use a quick After Effects comp to crop to 1024 only if the edit suite can’t handle it.
Sorry, but that’s the best I can suggest!
thanks for posting,
Mike
February 24th, 2010 at 1:15 pm
Thanks Mike,
This is the best and simplest explanation for aspect ratios I have ever read. And considering it’s been confusing me for years it’s just what I needed to read!
March 1st, 2010 at 11:08 am
Great post,
This makes the 16×9 problems for me al lot better to understand. Also the fact that it is related to Adobe Premiere is very welcome.
From now on I will save my work for the web wit 1050 pixels.
Greetings from The Netherlands
Bas Timmermans
April 5th, 2010 at 3:32 pm
Hi Mike
I’ve been trying to work non-square-pixel thing out in the last couple years. Also because HD to SD up- and downscalers also render different results – some add black bars on the side of the SD picture, some just squeeze to fill. It seems everyone is doing something different. So I did some testing with both a 1024×576 and a 1050×576 graphic with a round circle. On almost all monitors the 1024×576 graphic looked right and undistorted (CRT and LCD broadcast monitors from Sony, JVC, Barco).
I still don’t get this. But I will keep working with the 1024×576 format.
April 20th, 2010 at 3:37 am
Great! I will use this in my new movie.
April 21st, 2010 at 9:37 am
Really fascinating post, I truly appreciate you taking the time to set this with each other for readers like myself.
April 29th, 2010 at 11:01 am
this sucks so much
made custop project in 1024×576 exported lossless and when tried to make dvd out of it in encore cs4 it wanted to go 4:3 just cause i didnt have freaking 1050,,,, and after interpreting i had this 13+13 black boarders on the sides ….. lucky me i had CS3 on the different equipment … it all worked with no problem there …
June 4th, 2010 at 1:22 pm
hi mike -
great post! it only leaves me with one question: if the 16×9 image sits inside the screen (which has to be compensated for by the 13 extra pixels on each side), what happens if you downscale hd footage (1920×1080 or 1280×720 pixels) for sd or simply even show it on 16×9 tv screens? this would leave black bars at the left and the right side as well, right (assuming you would want an undistorted image)? after all, the sd widescreen image isn’t really 16×9 (1050×576 scaled to 720×576) while the hd widescreen image is (1920×1080 or 1280×720).
i am curious to what your suggestion might be!
July 4th, 2010 at 11:55 pm
Bastian,
That’s a very good point. Short answer, I don’t know. But you’re right – in theory the downscaled HD image would be only 1024 pixels wide, so would need to sit inside the full (1050) image which I guess would give you those black bars, unless you repeated or stretched just the outermost few pixels?? An added complication here might be those HD codecs use rectangular pixels (cutting down on horizontal resolution), so they’re not square to begin with – although I guess there’s still 1920 theoretically square pixels for the purposes of your question…..
Hmmm… I’m not sure I’d want to recommend one way or the other.
You could try Todd Kopriva at Adobe (see first comment above) and see what his take on this is.
July 5th, 2010 at 12:43 am
This entire post is a fallacy. 1024 * 576 is a true 16:9 (square pixel) resolution if you’re working with 576 lines of resolution (PAL).
Yes- the final output needs to be resized to 720 pixels wide (720*576) for anamorphic widescreen PAL output, but this is the case if you create it at 1050 pixels too. This nonsense change has been perpetrated by people who don’t understand how computers and broadcast output works. Just because “people at the BBC” do it, is absolutely no guarantee it is correct!
July 5th, 2010 at 12:46 am
And just to re-iterate, 1050*576 pixels is not a “Square Pixel” aspect ratio of 1.0 at 16:9. Do the math!
July 5th, 2010 at 11:15 am
Hi Dan,
Digital pictures are wider than analogue, so the 16×9 portion (1024 pixels) sits inside the full 1050 width. For the final output to avoid distortion it’s the full 1050 pixels (16×9 image, plus digital blanking) that should be squeezed down to 720.
Having said that, plenty of professionals have used 1024 quite happily (and continue to do so – even at the BBC!) – the only result being an ever so slightly distorted final broadcast image. I would suggest using 1050 if you’re particularly concerned about mapping the image correctly. If you can live with very slight distortion (that hardly anyone will notice) then 1024 should still be OK for your purposes.
July 22nd, 2010 at 6:47 pm
Dear Mike!
We just tested it, and the square 1050×576 as 16:9 and 788×576 as 4:3 source produce oval circle on the broadcast displays.
from Mike: “But the 4×3 image (702 pixels wide) sits inside those 720 pixels.”
This is not true!
The broadcast displays not only crop 9-9 pixels from the sides, but 7-7 pixels from the top and bottom of the pictures.
Because it, you can produce 720×576 material with 4:3 aspect rate, the cropping from both sides and from top,bottom will ensure, that the aspect rate will be preserved.
720/576 = 702/562
This is a well know behavior, and every broadcast product know about it. Every broadcast product use 720×576 materials with 4:3 aspect rate.
The 1050×576 and 788×576 square pixel sources are simple wrong, don’t use it.
Don’t forget about the top and bottom cropping!
Best regards: Balazs from tv2
July 22nd, 2010 at 7:45 pm
Hi Balázs,
Thanks for your comments. But you shouldn’t be getting distorted images by using 1050 as your original square pixel source. And you definitely shouldn’t be losing vertical resolution, so I can only assume that something is wrong with your workflow.
Maybe double check that the 1050 wide After Effects comp was definitely the PAL D1/DV Widescreen Square Pixel preset – and that the output module was definitely creating 720 X 576 files. Like I say, you shouldn’t be losing pixels top or bottom at all (I’m not talking here about text safe / action safe – which is something else entirely).
Honestly this is right, and does work.
Best regards,
Mike
July 23rd, 2010 at 12:09 pm
Mike “And you definitely shouldn’t be losing vertical resolution, so I can only assume that something is wrong with your workflow…… Like I say, you shouldn’t be losing pixels top or bottom at all”
Plese belive me, and belive Hannes too. An general display (CRT or even LCD and Plasma TV) will crop the top and bottom too, if the sides will be cropped.
Best regards: Balázs
July 23rd, 2010 at 1:22 pm
I do believe you – of course you might lose some picture when broadcast (see Action/Text safe comment above), but that’s not what this post is about.
I also believe you when you say that your tests produced distorted images. But they shouldn’t, provided you’re doing things properly.
Did you check the Comp settings and the Output module settings ??
Are you broadcasting in widescreen?
Best regards,
Mike
August 5th, 2010 at 5:59 pm
I skipped CS4 and having just upgraded to CS5 I’m frankly horrified by this change. I’ve read the explanation and frankly I think it’s wrong. Yes, TV pixels are non-square – at least for SD broadcasts. We all know that. For PAL DTV broadcast the image is squeezed to 720*576 (producing a non-square pixel aspect ratio). Same as DVD video.
But HD resolutions (like 1920 *1080 and 1280 * 720) use square pixels. Some HD formats, like HD-CAM use stretched pixel resolutions to reduce horizontal resolution (to 1440 wide IIRC) while maintaining the picture aspect ratio.
For SD work, this 1050 thing… well the maths simply doesn’t add up. 1050*576 is not a 16:9 ratio when using square pixels. You can see this very simply by using a calculator.
16 / 9 = 1.7 (recurring)
1024 / 576 = 1.7 (recurring)
1050 / 576 = 1.822916 (recurring)
As you can see, 1024*576 shares the same ratio as 16*9. Why? Because it is the proportionally scaled and correct version of a 16:9, 576 pixels high image.
Just because *some* digital cameras and broadcast gear don’t capture the full picture area and put black bars on the side, doesn’t mean you should start messing around with what were correct settings. The problem lies with those devices – not After Effects.
And also, regarding MPEG stream clip – the black bars you’re seeing will appear in quicktime player with any small video file (for example 320*180). It’s just a visual anomaly of Quicktime player – it disappears if you scale up the window.
August 5th, 2010 at 10:47 pm
Hi Dan,
I can see how the maths might look a bit screwy, but that’s because the actual ‘16×9′ image area (1024 pixels wide) sits inside those 1050 pixels. You do still need the extra pixels though (even though they’re not part of the 16×9 picture area) – otherwise the end result (after going via 720 to a widescreen TV) will be a wee bit distorted. Not by much, but still noticeable I think.
Regarding MPEG Streamclip – no honestly, black strips encoded. Not some QT window-resizing issue. This is a 1024×576 lossless MOV opened in MPEG Steamclip and exported to MPEG-4 using the 720×576 (DV-PAL) preset. I just checked – pulled the new MP4 file back into After Effects – a 720 wide clip with the actual picture occupying (roughly) the middle 702 pixels – which equates to the image occupying the centre 1024 pixels of a 1050-wide image.
August 14th, 2010 at 9:11 pm
Well, I also ran into this problem today. When I export it out, I stretch the image back to DV PAL. In (for example) Final Cut I check the anamorphic check box and the picture is back to normal. I do not know if this is the right way to solve the problem, but this works for me (at least looks right).