Question about widescreen resolution

AJRevitt · 27-08-2010, 23:59

I just want to clear something up. I believe that 4:3 PAL resolution signal is 576 X 720. But does a SD widescreen 16:9 picture have the same resolution? If so, does this mean that 16:9 standard definition pictures, although wider, have less detail than a 4:3 picture?

snotrageater · 28-08-2010, 00:05

Quote:

Originally Posted by AJRevitt

I just want to clear something up. I believe that 4:3 PAL resolution signal is 576 X 720. But does a SD widescreen 16:9 picture have the same resolution? If so, does this mean that 16:9 standard definition pictures, although wider, have less detail than a 4:3 picture?

When it comes to standard definition , any 16:9 image is simply a 4:3 image stretched to fill the screen so technically you could say they are less detailed.

The BBC have taken it one step further and now when they show programmes made in 4:3 they air them pillarboxed within a 16:9 frame.

They do send out signals to tell your tv to change to 4:3 but if you activate the text service you'll see the 16:9 box with the 4:3 image within it.

HD on the other hand is 16:9 in its native format but sd is 4:3 which is why the Widescreen Switching Signal is used for 16:9 broadcasts

IslandNiles · 28-08-2010, 00:19

Quote:

Originally Posted by snotrageater

When it comes to standard definition , any 16:9 image is simply a 4:3 image stretched to fill the screen so technically you could say they are less detailed.

The BBC have taken it one step further and now when they show programmes made in 4:3 they air them pillarboxed within a 16:9 frame.

They do send out signals to tell your tv to change to 4:3 but if you activate the text service you'll see the 16:9 box with the 4:3 image within it.

HD on the other hand is 16:9 in its native format but sd is 4:3 which is why the Widescreen Switching Signal is used for 16:9 broadcasts

This isn't correct at all, is it??

bobcar · 28-08-2010, 01:46

Quote:

Originally Posted by IslandNiles

This isn't correct at all, is it??

It is sort of (though not completely) but really it's all meaningless. You can say anything is the "native resolution" it doesn't mean anything at all.

What you look at is the resolution displayed on the screen and much more importantly how much compression there is - whether the format was originally 4:3 and has switching doesn't matter a jot and anyone who says it does doesn't understand anything about video. (Basically specifying HD as native 16:9 and so saying you couldn't have 4:3 and switching (or 2.35:1 and switching) is silly - you can't but that is a mistake by the specifiers rather than anything inherent).

IslandNiles · 28-08-2010, 01:56

But to say that any 16:9 image is simply a 4:3 image stretched to fit the screen is nonsense, isn't it? Maybe I'm completely wrong, but surely even SD programmes that are filmed and broadcast in widescreen are indeed natively widescreen and not 4:3 images stretched. (I know there was (is?) an issue with Freeview where no true widescreen was possible, but that's a separate issue.)

pocatello · 28-08-2010, 07:11

Its all 1's and 0's, there is no 4:3 on the disc or bit stream, its just a matter of how its told to display the resolution data. Animorphic digital data is just a metaphore. If its an animorphic bit stream then the wide screen tv will display the full picture. If its not, and there are encoded black bars encoded into the 4:3 picture, the resolution is going to be lower once they are cropped out.

Nigel Goodwin · 28-08-2010, 10:12

If it's a standard analogue transmission, then yes, widescreen is considerably lower resolution, because it's stretched to fit the screen and part of it is lost.

However, you need to consider the source as well - only a few years ago a team were sent out to film my daughters band (a specific song my daughter had written). I was admiring their camera, and asked why there were two pieces of masking tape across the top and bottom of the monitor, to be told it's to make the display widescreen, and the 4:3 recorded image will be chopped down to 16:9 in the editting suite.

Needless to say, I was horrified

As for the recording, it was never shown

The programme went out Sunday night, and the sequence was cut on the Friday as the show was over running.

snotrageater · 28-08-2010, 12:32

Quote:

Originally Posted by IslandNiles

But to say that any 16:9 image is simply a 4:3 image stretched to fit the screen is nonsense, isn't it? Maybe I'm completely wrong, but surely even SD programmes that are filmed and broadcast in widescreen are indeed natively widescreen and not 4:3 images stretched. (I know there was (is?) an issue with Freeview where no true widescreen was possible, but that's a separate issue.)

While the 16:9 programmes are produced in widescreen , their broadcast in sd is 4:3 stretched to fill the screen.

Do you not even know what the Widescreen Switching Signal does?

True widescreen is not available in sd whether it be Freesat /Freeview or any other source

Jarrak · 28-08-2010, 12:55

Quote:

Originally Posted by snotrageater

True widescreen is not available in sd whether it be Freesat /Freeview or any other source

Well it depends if you don't consider anamorphic widescreen relevant, a show is produced in anamorphic and then delivered via DVD or broadcast SD the STB or TV can then expand the compressed 4:3 carrier to provide the viewer with the native widescreen image as intended by the production company/channel.
To the viewer it's widescreen showing far more of the image than if the same widescreen source master was pan&scanned or centre cut and broadcast as a 4:3 ratio image.

snotrageater · 28-08-2010, 12:57

Quote:

Originally Posted by pocatello

Its all 1's and 0's, there is no 4:3 on the disc or bit stream, its just a matter of how its told to display the resolution data. Animorphic digital data is just a metaphore. If its an animorphic bit stream then the wide screen tv will display the full picture. If its not, and there are encoded black bars encoded into the 4:3 picture, the resolution is going to be lower once they are cropped out.

The sidebars are not encoded into an sd picture .
The sidebars are there because the sd image is basically 4:3 unless it's an anamorphic image in which case WSS will stretch it to fill the 16:9 screen.

Sidebars ARE encoded into an HD broadcast if the content is 4:3 .

DVD's of The Prisoner and Star Trek TOS are 4:3 and the sidebars are empty screen.
The Blurays of both programmes are full 16:9 (as are all Blurays) but the image is 4:3 and the sidebars are part of the recorded content which is why you cannot stretch it on your tv - only zoom

snotrageater · 28-08-2010, 13:00

Quote:

Originally Posted by Jarrak

Well it depends if you don't consider anamorphic widescreen relevant, a show is produced in anamorphic and then delivered via DVD or broadcast SD the STB or TV can then expand the compressed 4:3 carrier to provide the viewer with the native widescreen image as intended by the production company/channel.
To the viewer it's widescreen showing far more of the image than if the same widescreen source master was pan&scanned or centre cut and broadcast as a 4:3 ratio image.

Anamorphic widescreen - in an sd broadcast situation - is not true widescreen in the same way that an HD widescreen broadcast is .
As you say , its 4:3 expanded into 16:9 so you get the native widescreen image but its still really only 4:3 stretched.

So while you get the entire 16:9 image the quality is still only the same as a 4:3 .

scottie55 · 28-08-2010, 13:46

Quote:

Originally Posted by Nigel Goodwin

If it's a standard analogue transmission, then yes, widescreen is considerably lower resolution, because it's stretched to fit the screen and part of it is lost.

Is that true? What gets lost?

Last edited by scottie55 : 28-08-2010 at 13:47. Reason: ok ignore this. I understand now.

Nigel Goodwin · 28-08-2010, 14:37

Quote:

Originally Posted by scottie55

Is that true? What gets lost?

Yes it is true, part of the SCREEN RESOLUTION gets lost, not part of the picture

Watching analogue terrestrial reception, switch the set to 4:3 - that is what the picture you're receiving is, it will have big black bars at the sides, and black bars top and bottom. The small picture in the middle is how much actual 'picture' and resolution you're getting. It's then stretched vertically and horizontally to fill the screen.

IslandNiles · 28-08-2010, 14:39

Quote:

Originally Posted by Nigel Goodwin

Yes it is true, part of the SCREEN RESOLUTION gets lost, not part of the picture

Watching analogue terrestrial reception, switch the set to 4:3 - that is what the picture you're receiving is, it will have big black bars at the sides, and black bars top and bottom. The small picture in the middle is how much actual 'picture' and resolution you're getting. It's then stretched vertically and horizontally to fill the screen.

Right, but surely this isn't the same for DVDs and even for Sky.

Tassium · 28-08-2010, 14:42

Quote:

Originally Posted by snotrageater

Anamorphic widescreen - in an sd broadcast situation - is not true widescreen in the same way that an HD widescreen broadcast is .
As you say , its 4:3 expanded into 16:9 so you get the native widescreen image but its still really only 4:3 stretched.

So while you get the entire 16:9 image the quality is still only the same as a 4:3 .

You are looking at this the wrong way.

Widescreen images do not have to have "square pixels" to be considered "true".

And in fact SD over Freeview/DVDs does not use square pixels.

After all the resolution would have to be 768x576 for a 4:3 image, when over Freeview it's 720x576 (typically)

There is no "stretching", the stored pixels are decoded to be displayed at their appropriate aspect ratio.

Nigel Goodwin · 28-08-2010, 14:48

Quote:

Originally Posted by IslandNiles

Right, but surely this isn't the same for DVDs and even for Sky.

It depends on the source, but both DVD and Sky are DIGITAL sources (as is Freeview), it's the old analogue terrestrial wghich is ONLY 4:3.

Anyway, got to go now - I've bought myself a new computer monitior, a 24 inch widescreen one

Time to unpack it and get it set up.

Back later.

IslandNiles · 28-08-2010, 14:52

But they're still SD sources. The OP said that all SD pictures were 4:3 images stretched.

Tassium · 28-08-2010, 15:04

Quote:

Originally Posted by IslandNiles

But to say that any 16:9 image is simply a 4:3 image stretched to fit the screen is nonsense, isn't it? Maybe I'm completely wrong, but surely even SD programmes that are filmed and broadcast in widescreen are indeed natively widescreen and not 4:3 images stretched. (I know there was (is?) an issue with Freeview where no true widescreen was possible, but that's a separate issue.)

That's correct, dispite all appearances there is no stretching.

Why some people are confused is because they think that "pixels" are always square when in fact they can be rectangle.

And Freeview does do "true widescreen" (if we say 16:9 is wide),

The aspect ratio of the pixels is 16:9, as opposed to 4:3 for.. 4:3

4:3 aspect ratio with square pixels would be 768x576, so even 4:3 over Freeview does not use square pixels.

bobcar · 28-08-2010, 15:40

Quote:

Originally Posted by Nigel Goodwin

It depends on the source, but both DVD and Sky are DIGITAL sources (as is Freeview), it's the old analogue terrestrial wghich is ONLY 4:3.

There is no actual inherent aspect ratio present in an analogue signal because you are dealing with 2 different physical properties - time/amplitude for the horizontal and lines for the vertical. Yes it was originally intended to be used for 4:3 pictures but that doesn't make any subsequent different use (16:9) invalid.

Whether a picture is 4:3 or 16:9 (or 2.35:1) depends entirely on the programme content not the delivery method.

You could argue that for digital where you have pixels both horizontal and vertical that there is a natural aspect ratio but that does depend on the pixels being square.

prankz · 28-08-2010, 15:44

I just thought the thread was called windscreen resolution

snotrageater · 28-08-2010, 15:45

Quote:

Originally Posted by Tassium

That's correct, dispite all appearances there is no stretching.

.

One has to wonder what the widescreen switching signal is for then?
The WSS is present on all 16:9 sd whether it be Freeview , Freesat,Virgin or dvd.

Take the WSS away and you are left with a 4:3 image .

Analogue does not broadcast in anamorphic format.

And the reason that 16:9 tv and dvd uses the anamorphic system is because sd is 4:3 - end of story.

If it was possible to broadcast a full sd 16:9 image without anamorphic enhancement you would not require the WSS.

snotrageater · 28-08-2010, 15:51

Quote:

Originally Posted by bobcar

.

Whether a picture is 4:3 or 16:9 (or 2.35:1) depends entirely on the programme content not the delivery method.

.

Using that logic you are saying that a 2.35:1 image delivered via analogue C4 would be the same quality as 2.35:1 delivered via anamorphic widescreen on dvd or DTT- which is clearly nonsense.

The anamorphic enhancement used for dvd and digital tv means that you can get the full quality of the 4:3 box rather than losing quality in the black bars necessary by letterboxing.

Using your logic there is no difference between a letterboxed dvd of a 16:9 picture and an anamorphic dvd with 16:9 picture.

And thats the reason anamorphic widescreen was introduced - because sd images are 4;3 and without the WSS you need to letterbox the picture and the black bars are lost quality.

No such problems or need for anamorphic widescreen on HD as its native image is 16:9

Pugwash69 · 28-08-2010, 15:53

Quote:

Originally Posted by AJRevitt

I just want to clear something up. I believe that 4:3 PAL resolution signal is 576 X 720. But does a SD widescreen 16:9 picture have the same resolution? If so, does this mean that 16:9 standard definition pictures, although wider, have less detail than a 4:3 picture?

So to summarise, widescreen SD is still 720 columns by 576 lines but the pixels are less tall. You have the same level of detail but a different shape.

snotrageater · 28-08-2010, 15:54

Quote:

Originally Posted by IslandNiles

But they're still SD sources. The OP said that all SD pictures were 4:3 images stretched.

WIDESCREEN sd images are 4:3 stretched.
This is why you set up your dvd player by telling it whether you have a 16:9 tv screen.
When you tell it you have a 16:9 set this instructs the player to send the WSS signal to the tv to stretch the image.

Without the WSS the player will send the 16:9 image out as 4:3 letterbox meaning lost quality via the black bars.

WSS is present on widescreen sd whether it be Freeview , dvd or any digital tv source.

Take the WSS away and you get a squeezed 4:3 image.(if the image is 16:9)

Tassium · 28-08-2010, 16:21

Quote:

Originally Posted by snotrageater

One has to wonder what the widescreen switching signal is for then?
The WSS is present on all 16:9 sd whether it be Freeview , Freesat,Virgin or dvd.

Take the WSS away and you are left with a 4:3 image .

Analogue does not broadcast in anamorphic format.

And the reason that 16:9 tv and dvd uses the anamorphic system is because sd is 4:3 - end of story.

If it was possible to broadcast a full sd 16:9 image without anamorphic enhancement you would not require the WSS.

Sorry, this is all very mixed up stuff.

27-08-2010, 23:59	#1
AJRevitt Inactive Member Join Date: Mar 2010 Location: South Yorkshire, Emley Moor TX Posts: 1,053	Question about widescreen resolution I just want to clear something up. I believe that 4:3 PAL resolution signal is 576 X 720. But does a SD widescreen 16:9 picture have the same resolution? If so, does this mean that 16:9 standard definition pictures, although wider, have less detail than a 4:3 picture?

28-08-2010, 00:05	#2
snotrageater Inactive Member Join Date: Jul 2010 Posts: 635	Quote: Originally Posted by AJRevitt I just want to clear something up. I believe that 4:3 PAL resolution signal is 576 X 720. But does a SD widescreen 16:9 picture have the same resolution? If so, does this mean that 16:9 standard definition pictures, although wider, have less detail than a 4:3 picture? When it comes to standard definition , any 16:9 image is simply a 4:3 image stretched to fill the screen so technically you could say they are less detailed. The BBC have taken it one step further and now when they show programmes made in 4:3 they air them pillarboxed within a 16:9 frame. They do send out signals to tell your tv to change to 4:3 but if you activate the text service you'll see the 16:9 box with the 4:3 image within it. HD on the other hand is 16:9 in its native format but sd is 4:3 which is why the Widescreen Switching Signal is used for 16:9 broadcasts

28-08-2010, 00:19	#3
IslandNiles Forum Member Join Date: Apr 2005 Posts: 13,091	Quote: Originally Posted by snotrageater When it comes to standard definition , any 16:9 image is simply a 4:3 image stretched to fill the screen so technically you could say they are less detailed. The BBC have taken it one step further and now when they show programmes made in 4:3 they air them pillarboxed within a 16:9 frame. They do send out signals to tell your tv to change to 4:3 but if you activate the text service you'll see the 16:9 box with the 4:3 image within it. HD on the other hand is 16:9 in its native format but sd is 4:3 which is why the Widescreen Switching Signal is used for 16:9 broadcasts This isn't correct at all, is it??

28-08-2010, 01:46	#4
bobcar Forum Member Join Date: Sep 2004 Posts: 14,718	Quote: Originally Posted by IslandNiles This isn't correct at all, is it?? It is sort of (though not completely) but really it's all meaningless. You can say anything is the "native resolution" it doesn't mean anything at all. What you look at is the resolution displayed on the screen and much more importantly how much compression there is - whether the format was originally 4:3 and has switching doesn't matter a jot and anyone who says it does doesn't understand anything about video. (Basically specifying HD as native 16:9 and so saying you couldn't have 4:3 and switching (or 2.35:1 and switching) is silly - you can't but that is a mistake by the specifiers rather than anything inherent).

28-08-2010, 01:56	#5
IslandNiles Forum Member Join Date: Apr 2005 Posts: 13,091	But to say that any 16:9 image is simply a 4:3 image stretched to fit the screen is nonsense, isn't it? Maybe I'm completely wrong, but surely even SD programmes that are filmed and broadcast in widescreen are indeed natively widescreen and not 4:3 images stretched. (I know there was (is?) an issue with Freeview where no true widescreen was possible, but that's a separate issue.)

28-08-2010, 07:11	#6
pocatello Inactive Member Join Date: Mar 2010 Posts: 8,622	Its all 1's and 0's, there is no 4:3 on the disc or bit stream, its just a matter of how its told to display the resolution data. Animorphic digital data is just a metaphore. If its an animorphic bit stream then the wide screen tv will display the full picture. If its not, and there are encoded black bars encoded into the 4:3 picture, the resolution is going to be lower once they are cropped out.

28-08-2010, 10:12	#7
Nigel Goodwin Forum Member Join Date: Apr 2006 Location: North Derbyshire Posts: 41,789	If it's a standard analogue transmission, then yes, widescreen is considerably lower resolution, because it's stretched to fit the screen and part of it is lost. However, you need to consider the source as well - only a few years ago a team were sent out to film my daughters band (a specific song my daughter had written). I was admiring their camera, and asked why there were two pieces of masking tape across the top and bottom of the monitor, to be told it's to make the display widescreen, and the 4:3 recorded image will be chopped down to 16:9 in the editting suite. Needless to say, I was horrified As for the recording, it was never shown The programme went out Sunday night, and the sequence was cut on the Friday as the show was over running.

28-08-2010, 12:32	#8
snotrageater Inactive Member Join Date: Jul 2010 Posts: 635	Quote: Originally Posted by IslandNiles But to say that any 16:9 image is simply a 4:3 image stretched to fit the screen is nonsense, isn't it? Maybe I'm completely wrong, but surely even SD programmes that are filmed and broadcast in widescreen are indeed natively widescreen and not 4:3 images stretched. (I know there was (is?) an issue with Freeview where no true widescreen was possible, but that's a separate issue.) While the 16:9 programmes are produced in widescreen , their broadcast in sd is 4:3 stretched to fill the screen. Do you not even know what the Widescreen Switching Signal does? True widescreen is not available in sd whether it be Freesat /Freeview or any other source

28-08-2010, 12:55	#9
Jarrak Forum Member Join Date: Jan 2002 Location: Ilkeston Posts: 18,075	Quote: Originally Posted by snotrageater True widescreen is not available in sd whether it be Freesat /Freeview or any other source Well it depends if you don't consider anamorphic widescreen relevant, a show is produced in anamorphic and then delivered via DVD or broadcast SD the STB or TV can then expand the compressed 4:3 carrier to provide the viewer with the native widescreen image as intended by the production company/channel. To the viewer it's widescreen showing far more of the image than if the same widescreen source master was pan&scanned or centre cut and broadcast as a 4:3 ratio image.

28-08-2010, 12:57	#10
snotrageater Inactive Member Join Date: Jul 2010 Posts: 635	Quote: Originally Posted by pocatello Its all 1's and 0's, there is no 4:3 on the disc or bit stream, its just a matter of how its told to display the resolution data. Animorphic digital data is just a metaphore. If its an animorphic bit stream then the wide screen tv will display the full picture. If its not, and there are encoded black bars encoded into the 4:3 picture, the resolution is going to be lower once they are cropped out. The sidebars are not encoded into an sd picture . The sidebars are there because the sd image is basically 4:3 unless it's an anamorphic image in which case WSS will stretch it to fill the 16:9 screen. Sidebars ARE encoded into an HD broadcast if the content is 4:3 . DVD's of The Prisoner and Star Trek TOS are 4:3 and the sidebars are empty screen. The Blurays of both programmes are full 16:9 (as are all Blurays) but the image is 4:3 and the sidebars are part of the recorded content which is why you cannot stretch it on your tv - only zoom

28-08-2010, 13:00	#11
snotrageater Inactive Member Join Date: Jul 2010 Posts: 635	Quote: Originally Posted by Jarrak Well it depends if you don't consider anamorphic widescreen relevant, a show is produced in anamorphic and then delivered via DVD or broadcast SD the STB or TV can then expand the compressed 4:3 carrier to provide the viewer with the native widescreen image as intended by the production company/channel. To the viewer it's widescreen showing far more of the image than if the same widescreen source master was pan&scanned or centre cut and broadcast as a 4:3 ratio image. Anamorphic widescreen - in an sd broadcast situation - is not true widescreen in the same way that an HD widescreen broadcast is . As you say , its 4:3 expanded into 16:9 so you get the native widescreen image but its still really only 4:3 stretched. So while you get the entire 16:9 image the quality is still only the same as a 4:3 .

28-08-2010, 13:46	#12
scottie55 Forum Member Join Date: Aug 2009 Posts: 127	Quote: Originally Posted by Nigel Goodwin If it's a standard analogue transmission, then yes, widescreen is considerably lower resolution, because it's stretched to fit the screen and part of it is lost. Is that true? What gets lost? Last edited by scottie55 : 28-08-2010 at 13:47. Reason: ok ignore this. I understand now.

28-08-2010, 14:37	#13
Nigel Goodwin Forum Member Join Date: Apr 2006 Location: North Derbyshire Posts: 41,789	Quote: Originally Posted by scottie55 Is that true? What gets lost? Yes it is true, part of the SCREEN RESOLUTION gets lost, not part of the picture Watching analogue terrestrial reception, switch the set to 4:3 - that is what the picture you're receiving is, it will have big black bars at the sides, and black bars top and bottom. The small picture in the middle is how much actual 'picture' and resolution you're getting. It's then stretched vertically and horizontally to fill the screen.

28-08-2010, 14:39	#14
IslandNiles Forum Member Join Date: Apr 2005 Posts: 13,091	Quote: Originally Posted by Nigel Goodwin Yes it is true, part of the SCREEN RESOLUTION gets lost, not part of the picture Watching analogue terrestrial reception, switch the set to 4:3 - that is what the picture you're receiving is, it will have big black bars at the sides, and black bars top and bottom. The small picture in the middle is how much actual 'picture' and resolution you're getting. It's then stretched vertically and horizontally to fill the screen. Right, but surely this isn't the same for DVDs and even for Sky.

28-08-2010, 14:42	#15
Tassium Forum Member Join Date: Mar 2009 Location: It's Grim Posts: 24,412	Quote: Originally Posted by snotrageater Anamorphic widescreen - in an sd broadcast situation - is not true widescreen in the same way that an HD widescreen broadcast is . As you say , its 4:3 expanded into 16:9 so you get the native widescreen image but its still really only 4:3 stretched. So while you get the entire 16:9 image the quality is still only the same as a 4:3 . You are looking at this the wrong way. Widescreen images do not have to have "square pixels" to be considered "true". And in fact SD over Freeview/DVDs does not use square pixels. After all the resolution would have to be 768x576 for a 4:3 image, when over Freeview it's 720x576 (typically) There is no "stretching", the stored pixels are decoded to be displayed at their appropriate aspect ratio.

28-08-2010, 14:48	#16
Nigel Goodwin Forum Member Join Date: Apr 2006 Location: North Derbyshire Posts: 41,789	Quote: Originally Posted by IslandNiles Right, but surely this isn't the same for DVDs and even for Sky. It depends on the source, but both DVD and Sky are DIGITAL sources (as is Freeview), it's the old analogue terrestrial wghich is ONLY 4:3. Anyway, got to go now - I've bought myself a new computer monitior, a 24 inch widescreen one Time to unpack it and get it set up. Back later.

28-08-2010, 14:52	#17
IslandNiles Forum Member Join Date: Apr 2005 Posts: 13,091	But they're still SD sources. The OP said that all SD pictures were 4:3 images stretched.

28-08-2010, 15:04	#18
Tassium Forum Member Join Date: Mar 2009 Location: It's Grim Posts: 24,412	Quote: Originally Posted by IslandNiles But to say that any 16:9 image is simply a 4:3 image stretched to fit the screen is nonsense, isn't it? Maybe I'm completely wrong, but surely even SD programmes that are filmed and broadcast in widescreen are indeed natively widescreen and not 4:3 images stretched. (I know there was (is?) an issue with Freeview where no true widescreen was possible, but that's a separate issue.) That's correct, dispite all appearances there is no stretching. Why some people are confused is because they think that "pixels" are always square when in fact they can be rectangle. And Freeview does do "true widescreen" (if we say 16:9 is wide), The aspect ratio of the pixels is 16:9, as opposed to 4:3 for.. 4:3 4:3 aspect ratio with square pixels would be 768x576, so even 4:3 over Freeview does not use square pixels.

28-08-2010, 15:40	#19
bobcar Forum Member Join Date: Sep 2004 Posts: 14,718	Quote: Originally Posted by Nigel Goodwin It depends on the source, but both DVD and Sky are DIGITAL sources (as is Freeview), it's the old analogue terrestrial wghich is ONLY 4:3. There is no actual inherent aspect ratio present in an analogue signal because you are dealing with 2 different physical properties - time/amplitude for the horizontal and lines for the vertical. Yes it was originally intended to be used for 4:3 pictures but that doesn't make any subsequent different use (16:9) invalid. Whether a picture is 4:3 or 16:9 (or 2.35:1) depends entirely on the programme content not the delivery method. You could argue that for digital where you have pixels both horizontal and vertical that there is a natural aspect ratio but that does depend on the pixels being square.

28-08-2010, 15:44	#20
prankz Forum Member Join Date: Oct 2005 Location: London Posts: 1,400	I just thought the thread was called windscreen resolution

28-08-2010, 15:45	#21
snotrageater Inactive Member Join Date: Jul 2010 Posts: 635	Quote: Originally Posted by Tassium That's correct, dispite all appearances there is no stretching. . One has to wonder what the widescreen switching signal is for then? The WSS is present on all 16:9 sd whether it be Freeview , Freesat,Virgin or dvd. Take the WSS away and you are left with a 4:3 image . Analogue does not broadcast in anamorphic format. And the reason that 16:9 tv and dvd uses the anamorphic system is because sd is 4:3 - end of story. If it was possible to broadcast a full sd 16:9 image without anamorphic enhancement you would not require the WSS.

DS Forums

Question about widescreen resolution

28-08-2010, 15:51	#22
snotrageater Inactive Member Join Date: Jul 2010 Posts: 635	Quote: Originally Posted by bobcar . Whether a picture is 4:3 or 16:9 (or 2.35:1) depends entirely on the programme content not the delivery method. . Using that logic you are saying that a 2.35:1 image delivered via analogue C4 would be the same quality as 2.35:1 delivered via anamorphic widescreen on dvd or DTT- which is clearly nonsense. The anamorphic enhancement used for dvd and digital tv means that you can get the full quality of the 4:3 box rather than losing quality in the black bars necessary by letterboxing. Using your logic there is no difference between a letterboxed dvd of a 16:9 picture and an anamorphic dvd with 16:9 picture. And thats the reason anamorphic widescreen was introduced - because sd images are 4;3 and without the WSS you need to letterbox the picture and the black bars are lost quality. No such problems or need for anamorphic widescreen on HD as its native image is 16:9

28-08-2010, 15:53	#23
Pugwash69 Forum Member Join Date: Jan 2004 Location: The Sticks Posts: 3,720	Quote: Originally Posted by AJRevitt I just want to clear something up. I believe that 4:3 PAL resolution signal is 576 X 720. But does a SD widescreen 16:9 picture have the same resolution? If so, does this mean that 16:9 standard definition pictures, although wider, have less detail than a 4:3 picture? So to summarise, widescreen SD is still 720 columns by 576 lines but the pixels are less tall. You have the same level of detail but a different shape.

28-08-2010, 15:54	#24
snotrageater Inactive Member Join Date: Jul 2010 Posts: 635	Quote: Originally Posted by IslandNiles But they're still SD sources. The OP said that all SD pictures were 4:3 images stretched. WIDESCREEN sd images are 4:3 stretched. This is why you set up your dvd player by telling it whether you have a 16:9 tv screen. When you tell it you have a 16:9 set this instructs the player to send the WSS signal to the tv to stretch the image. Without the WSS the player will send the 16:9 image out as 4:3 letterbox meaning lost quality via the black bars. WSS is present on widescreen sd whether it be Freeview , dvd or any digital tv source. Take the WSS away and you get a squeezed 4:3 image.(if the image is 16:9)

28-08-2010, 16:21	#25
Tassium Forum Member Join Date: Mar 2009 Location: It's Grim Posts: 24,412	Quote: Originally Posted by snotrageater One has to wonder what the widescreen switching signal is for then? The WSS is present on all 16:9 sd whether it be Freeview , Freesat,Virgin or dvd. Take the WSS away and you are left with a 4:3 image . Analogue does not broadcast in anamorphic format. And the reason that 16:9 tv and dvd uses the anamorphic system is because sd is 4:3 - end of story. If it was possible to broadcast a full sd 16:9 image without anamorphic enhancement you would not require the WSS. Sorry, this is all very mixed up stuff.