I am fuming because a tape I carefully prepared in 16:9 was shown at an event recently in 4:3. I was not there but am told the projectionists claimed their professional equipment did not recognise the signal as 16:9.
The tape was full 16:9 - i.e. an anamorphic image, so that when shown "square" it would have had tall thin people.
Other people's 16:9 tapes were apparently recognised as such and played fine.
Should I be doing something special to mark the tapes 16:9? I had, naturally, labelled the box, the cassette and the leader of the film as 16:9. I edit on Premier Pro 1.5. Is there some setting I should make there to put a marker in the signal on the tape?
Dave
PS Yes, of course, the projection team should have relied on their eyes and not on the gear but if their projector was mounted on the high ceiling of a hall they probably could not adjust it "manually" (even by a remote control).
Is there a 16:9 marker?
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Dave Watterson
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Graeme Webb
Hi Dave,
That was unfortunate was it here in the UK? The only time I have provided anamorphic 16x9 for public viewing has been on DVD and the projectors have auto switched without any problems, I would have thought that if others had played OK so should yours, I am assuming that after running someone elses anamorphic tape it was switching back to 4x3 OK.
I had the same problem when I gave someone an anamorphic tape (there was a section on the entry form for this format) It turned out that they couldn't project anamorphic anyway. So since then I letterbox them in 4x3. At least they didn't loose your film or results which I believe can happen sometimes. I am not a Premier user but I have had a look in FCP to see if there is a signal marker and can't see anything on the 'print to tape option'. G
That was unfortunate was it here in the UK? The only time I have provided anamorphic 16x9 for public viewing has been on DVD and the projectors have auto switched without any problems, I would have thought that if others had played OK so should yours, I am assuming that after running someone elses anamorphic tape it was switching back to 4x3 OK.
I had the same problem when I gave someone an anamorphic tape (there was a section on the entry form for this format) It turned out that they couldn't project anamorphic anyway. So since then I letterbox them in 4x3. At least they didn't loose your film or results which I believe can happen sometimes. I am not a Premier user but I have had a look in FCP to see if there is a signal marker and can't see anything on the 'print to tape option'. G
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Dave Watterson
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I have been delving a bit into this field and it is FAR more complex than you might think. BUT - dealing only with SD here ...
So far as I can tell any system which detects 4:3 or 16:9 digital video does it by looking at the shape of the pixels. Basically 4:3 pixels are "nearly square" (1.067 to 1) 16:9 pixels are "oblong" (1.422 to 1).
That means that for the best chance of having a "widescreen" video recognised as such it should be recorded using "oblong" pixels.
Most systems which handle "widescreen" will use "oblong" pixels automatically. But it pays to check in the editing system, if possible, what pixel aspect ratio the software thinks it is using. In Premiere Pro there are various ways to examine the properties of a clip which will tell you this. You can also instruct Premiere to use the correct type of pixels. (In their jargon to "interpret" them as one ratio or the other.)
You should also be careful about what you output to.
Some DVD burning software allows you to check the pixel aspect ratio and, if necessary, to interpret the image as different types of pixel. If you output to a camera for tape copies make sure the camera is set to "widescreen" mode too.
Having said all that the practical position is complicated by the playback kit. Most DVD players, some tape players, many TV sets and most video projectors can stretch and squeeze images.
The only practical rules I can think of are:
1) make sure what you send out uses the appropriate shape of pixels and is clearly marked on disc, tape, leader etc
2) when projecting trust your eyes ... if you are showing 4:3 and people seem tall and thin switch to 16:9. And vice-versa. Do not depend on any automatic system. Actually I find it easier to look out for known shapes like circles. Keep an eye open for a car wheel, clock etc and any distortion will be immediately obvious.
Oh ... and in passing ... I discovered the answer to a question I raised in another thread ages ago. What happened to the 14:9 ratio we were told all television broadcasts would be using?
The answer is that in the UK at least the broadcast organisations are transmitting 14:9 images as a practical compromise. "Square" (4;3) television sets will just chop a little off the edges. "Wide" (16:9) television sets will expand the image to full width and chop a fraction off the top and bottom.
Dave (or rather D-A-V-E - in widescreen)
So far as I can tell any system which detects 4:3 or 16:9 digital video does it by looking at the shape of the pixels. Basically 4:3 pixels are "nearly square" (1.067 to 1) 16:9 pixels are "oblong" (1.422 to 1).
That means that for the best chance of having a "widescreen" video recognised as such it should be recorded using "oblong" pixels.
Most systems which handle "widescreen" will use "oblong" pixels automatically. But it pays to check in the editing system, if possible, what pixel aspect ratio the software thinks it is using. In Premiere Pro there are various ways to examine the properties of a clip which will tell you this. You can also instruct Premiere to use the correct type of pixels. (In their jargon to "interpret" them as one ratio or the other.)
You should also be careful about what you output to.
Some DVD burning software allows you to check the pixel aspect ratio and, if necessary, to interpret the image as different types of pixel. If you output to a camera for tape copies make sure the camera is set to "widescreen" mode too.
Having said all that the practical position is complicated by the playback kit. Most DVD players, some tape players, many TV sets and most video projectors can stretch and squeeze images.
The only practical rules I can think of are:
1) make sure what you send out uses the appropriate shape of pixels and is clearly marked on disc, tape, leader etc
2) when projecting trust your eyes ... if you are showing 4:3 and people seem tall and thin switch to 16:9. And vice-versa. Do not depend on any automatic system. Actually I find it easier to look out for known shapes like circles. Keep an eye open for a car wheel, clock etc and any distortion will be immediately obvious.
Oh ... and in passing ... I discovered the answer to a question I raised in another thread ages ago. What happened to the 14:9 ratio we were told all television broadcasts would be using?
The answer is that in the UK at least the broadcast organisations are transmitting 14:9 images as a practical compromise. "Square" (4;3) television sets will just chop a little off the edges. "Wide" (16:9) television sets will expand the image to full width and chop a fraction off the top and bottom.
Dave (or rather D-A-V-E - in widescreen)
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Brian Saberton
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It's all becoming a bit complicated and is compounded by the fact that a lot of people seem to be happy to watch 4 x 3 pictures in the 16 x 9 format and appear to be oblivious to the fact that images are then distorted. I think I said in a previous posting that films shown in the wrong aspect ratio drive me to distraction.
As far as my own home equipment is concerned my video projector has a 16 x 9 chip so I have my screen set at 16 x 9 and use the projectors remote control to switch through the different formats. In practice I use just two settings; one for 4 x 3 films and the other for 16 x 9 or scope (2.35 to 1). My TV is a bit more complicated and although it has an auto setting this merely translates all signals into 16 x 9. I've found that if I leave the setting on 4 x 3 the picture switches into the correct format (automatically!!) and I see programmes/films either transmitted or from DVD in the correct aspect ratio. It also has a 14 x 9 setting which crops 4 x 3 images at the top and bottom.
The projector we had at the club (a Sanyo) had a 4 x 3 chip and had to be manually switched into the 16 x 9 setting for anamorphic widescreen.
As far as my own home equipment is concerned my video projector has a 16 x 9 chip so I have my screen set at 16 x 9 and use the projectors remote control to switch through the different formats. In practice I use just two settings; one for 4 x 3 films and the other for 16 x 9 or scope (2.35 to 1). My TV is a bit more complicated and although it has an auto setting this merely translates all signals into 16 x 9. I've found that if I leave the setting on 4 x 3 the picture switches into the correct format (automatically!!) and I see programmes/films either transmitted or from DVD in the correct aspect ratio. It also has a 14 x 9 setting which crops 4 x 3 images at the top and bottom.
The projector we had at the club (a Sanyo) had a 4 x 3 chip and had to be manually switched into the 16 x 9 setting for anamorphic widescreen.
Brian Saberton
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Dave Watterson
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- Brian Sabertonfilms shown in the wrong aspect ratio drive me to distraction.
If you want to give yourself a real nervous shock start by looking at this:
http://www.sciencemedianetwork.org/Pixel_Aspect_Ratio
You can work you way onwards from there.
Essentially nothing is as it seems:
in the UK we believe our tv uses 625 lines - wrong
we believe our own video is right at 720 by 576 - wrong
and so on and on.
The only heartening thing is that the differences are very small and not so obvious as showing a 4:3 film in 16:9 or vice-versa. I had to have a little lie down after exploring the topic for a while!
Dave
Connected with this topic......
TV companies like the national BBC Tag their transmissions. When they transmit their pictures, they put some sort of eletronic marker in the signal to tell televisions that it`s a Widescreen Transnission.
Local BBC like BBC South (when they do their local News items) transmit in 14/9! You get a very thin black bars each side of the picture. Why the hell do they do 14/9 is beyond me!
You can always tell when the programme is coming locally, because of this stupid format!
As a subnote to other geeks. When Channel 4 had testcards in the 80`s, you could tell that the testcard was generated by the local transmitter (in my case Rowridge here on the Island) because the letters CH4 had a line above and below the letters.
Geek mode over....
Bye for now and be good......
Stingman
TV companies like the national BBC Tag their transmissions. When they transmit their pictures, they put some sort of eletronic marker in the signal to tell televisions that it`s a Widescreen Transnission.
Local BBC like BBC South (when they do their local News items) transmit in 14/9! You get a very thin black bars each side of the picture. Why the hell do they do 14/9 is beyond me!
You can always tell when the programme is coming locally, because of this stupid format!
As a subnote to other geeks. When Channel 4 had testcards in the 80`s, you could tell that the testcard was generated by the local transmitter (in my case Rowridge here on the Island) because the letters CH4 had a line above and below the letters.
Geek mode over....
Bye for now and be good......
Stingman
Ian Gardner
Film Maker
Film Maker
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Dave Watterson
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chrisk
Widescreen switching
Hi All
A video signal sent to a TV or projector is normally in analogue form via s-video, composite or component video and pixels do not exist in this form. The display device therefore cannot recognise 'oblong' or 'square' pixels and must be told what aspect ratio to display the picture.
The instruction is called WSS (Widescreen Switching Signal) and is included nominally in line 23 of a PAL 576i frame. Line 23 is the first line of the active video content. The WSS data can provide 8 different codes covering 4:3, 14:9, 16:9, >16:9 ratios in full or letterbox format. This WSS method is employed in broadcast transmissions and you would expect it to be generated by widescreen camcorders and retained or generated by properly configured editing systems. However I'm sure that it can't always be relied on to automatically set the system correctly.
Another method used for widescreen signalling uses different voltages on pin 8 of a SCART connector, but obviously can only be used with SCART and I don't think is universally adopted.
I agree that the safest way is to properly mark the tape or DVD in several ways in the hope that it is spotted by the projectionist who will then use manual settings to display in the correct ratio.
My own InFocus projector is natively 16:10 ratio which is correct for widescreen computer display. It also has 16:9 and 4:3 options for video display. These settings work well but when set to 4:3 the picture height is the same as that used for 16:10 (fine for 4:3 computers) so if 16:9 video is set up to fill a proper 16:9 screen, when switching to 4:3 the picture overlaps top and bottom so the projector zoom and tilt have to be changed. Most annoying as it should have been so easy for InFocus to provide another 4:3 video setting that allowed a 4:3 picture to fit in the 16:9 screen, just as in any widescreen TV.
I will do some tests using the limited equipment available to me (Canon XL2 true widescreen, Sony TRV900 letterbox, InFocus 16:10 and NEC 4:3 projectors, several TV sets, Premiere Pro 2) to determine what combinations work automatically. If anyone is interested I will report back.
Chris
A video signal sent to a TV or projector is normally in analogue form via s-video, composite or component video and pixels do not exist in this form. The display device therefore cannot recognise 'oblong' or 'square' pixels and must be told what aspect ratio to display the picture.
The instruction is called WSS (Widescreen Switching Signal) and is included nominally in line 23 of a PAL 576i frame. Line 23 is the first line of the active video content. The WSS data can provide 8 different codes covering 4:3, 14:9, 16:9, >16:9 ratios in full or letterbox format. This WSS method is employed in broadcast transmissions and you would expect it to be generated by widescreen camcorders and retained or generated by properly configured editing systems. However I'm sure that it can't always be relied on to automatically set the system correctly.
Another method used for widescreen signalling uses different voltages on pin 8 of a SCART connector, but obviously can only be used with SCART and I don't think is universally adopted.
I agree that the safest way is to properly mark the tape or DVD in several ways in the hope that it is spotted by the projectionist who will then use manual settings to display in the correct ratio.
My own InFocus projector is natively 16:10 ratio which is correct for widescreen computer display. It also has 16:9 and 4:3 options for video display. These settings work well but when set to 4:3 the picture height is the same as that used for 16:10 (fine for 4:3 computers) so if 16:9 video is set up to fill a proper 16:9 screen, when switching to 4:3 the picture overlaps top and bottom so the projector zoom and tilt have to be changed. Most annoying as it should have been so easy for InFocus to provide another 4:3 video setting that allowed a 4:3 picture to fit in the 16:9 screen, just as in any widescreen TV.
I will do some tests using the limited equipment available to me (Canon XL2 true widescreen, Sony TRV900 letterbox, InFocus 16:10 and NEC 4:3 projectors, several TV sets, Premiere Pro 2) to determine what combinations work automatically. If anyone is interested I will report back.
Chris
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Dave Watterson
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Well I would certainly be interested, Chris.
You are right, of course, about the last link to the projector almost always being analogue - though that may change in future. InFocus machines then have the excellent Faroujia scaler inside to make changes - at least mine does.
But what happens earlier in the chain?
As for warnings ... in the case that got me going I had marked on the cassette box and on the cassette itself that it was 16:9. I had superimposed on the whole 20 seconds black leader and Premiere countdown a box saying "16:9". The entry form was marked 16:9.
And the projectionists refused to believe it ... even though the picture distortion was obvious to the audience!
While you are delving into this area, can you shed any light on what I call the "he Pinnacl" problem ...? The excellent film "The Pinnacle" was shown all over the place in the last few years with only the centre section of its widescreen image projected. The image was correctly proportioned - no tall thin people or short fat ones - just the edges of the image had vanished.
Dave
You are right, of course, about the last link to the projector almost always being analogue - though that may change in future. InFocus machines then have the excellent Faroujia scaler inside to make changes - at least mine does.
But what happens earlier in the chain?
As for warnings ... in the case that got me going I had marked on the cassette box and on the cassette itself that it was 16:9. I had superimposed on the whole 20 seconds black leader and Premiere countdown a box saying "16:9". The entry form was marked 16:9.
And the projectionists refused to believe it ... even though the picture distortion was obvious to the audience!
While you are delving into this area, can you shed any light on what I call the "he Pinnacl" problem ...? The excellent film "The Pinnacle" was shown all over the place in the last few years with only the centre section of its widescreen image projected. The image was correctly proportioned - no tall thin people or short fat ones - just the edges of the image had vanished.
Dave
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chrisk
Hi Dave
Thanks for your interest. When projecting videos at the club or home I have often noticed that automatic switching sometimes happens but more often does not. I have put this down to the vagaries of the various equipment and media combinations that have been used. I will look into this more rigorously, but as I say with only limited access to various items of equipment the results will be of interest to me but not necessarily to those with other combinations.
I don't recall seeing 'The Pinnacle' in either widescreen or 4:3 format. Are you talking about film or video projection? It is quite normal to 'Pan and Scan' to bring out part of a widescreen video for 4:3 display or I believe there is a 'centre of interest' signal that can be added to a widescreen video to instruct the TV or projector to display a 4:3 picture centred on this point. I don't know how it works.
Thanks for your interest. When projecting videos at the club or home I have often noticed that automatic switching sometimes happens but more often does not. I have put this down to the vagaries of the various equipment and media combinations that have been used. I will look into this more rigorously, but as I say with only limited access to various items of equipment the results will be of interest to me but not necessarily to those with other combinations.
I don't recall seeing 'The Pinnacle' in either widescreen or 4:3 format. Are you talking about film or video projection? It is quite normal to 'Pan and Scan' to bring out part of a widescreen video for 4:3 display or I believe there is a 'centre of interest' signal that can be added to a widescreen video to instruct the TV or projector to display a 4:3 picture centred on this point. I don't know how it works.
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billyfromConsett
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If you can get your hands on a copy of "he Pinnacl" then it might give you a chance of working it out.
If it plays properly on your kit (unlikely if it has gone repeatedly wrong on tour) then there must be some projector picking and choosing only to play the central bit of the image.
I'd suspect that the movie has gone through an editing app that was outputted to 4:3, and just binned the rest.
At our club I set the DVD player to play DVD's letterboxed only if necessary (so there must be a sensor), and they would always look right. 16:9 MiniDV's need a manual alteration of the projector. We're at the point now of having a projector that can easily switch formats (Panasonic PT-AX200), so we'll see if the tapes people send us from now on, let us watch 16:9 properly.
If it plays properly on your kit (unlikely if it has gone repeatedly wrong on tour) then there must be some projector picking and choosing only to play the central bit of the image.
I'd suspect that the movie has gone through an editing app that was outputted to 4:3, and just binned the rest.
At our club I set the DVD player to play DVD's letterboxed only if necessary (so there must be a sensor), and they would always look right. 16:9 MiniDV's need a manual alteration of the projector. We're at the point now of having a projector that can easily switch formats (Panasonic PT-AX200), so we'll see if the tapes people send us from now on, let us watch 16:9 properly.
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FILM THURSO
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