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2.35:1 aspect ratio on a 16x9 anamorphic dvd


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#1 coolbreeze

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Posted 28 February 2006 - 10:43 AM

A lot of the work ive shot recently has been super 35 for a 2.35:1 aspect ratio, and as im in the middle of posting these at the moment ive come across something that i need a little help getting my head around.

Why is it that a film with a 2.35:1 aspect ratio, played out to a 16x9 dvd with a 2.35:1 letterbox, being viewed on a correctly set up dvd player and a correctly set up widescreen Tv gives me an image that looks like its a squeezed 2:1 aspect ratio? The dvd player is set up to out put a 16x9 image and the widescreen tv is set up to receive a 16x9 image. I know the idea is to use more pixels but surely we shouldnt all be watching a squeezed image so that the aspect ratio as we view it has for all intents and purposes changed? I know the images havent been cropped but we arent viewing them as intended - does this make sense?

Is there any way of getting a true 2.35:1 aspect ratio on an anamorphic dvd? All the telecine guys are looking at me like im mad!?

Sincerely,
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#2 Stephen Williams

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Posted 28 February 2006 - 11:18 AM

A lot of the work ive shot recently has been super 35 for a 2.35:1 aspect ratio, and as im in the middle of posting these at the moment ive come across something that i need a little help getting my head around.

Is there any way of getting a true 2.35:1 aspect ratio on an anamorphic dvd? All the telecine guys are looking at me like im mad!?

Sincerely,


Hi,

You will have to encode the Black top + bottom from 2.35:1 to 1.78:1. Then it will play correctly.

Stephen
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#3 David Mullen ASC

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Posted 28 February 2006 - 11:19 AM

Perhaps your 16x9 TV is set-up incorrectly -- mine has additional options for stretching and squeezing for people that want to fill a 16x9 set in different ways.

A DVD is standard def and can only have two types of signals: 4x3 or 16x9. That's it. Any other aspect ratios are achieved by letterboxing. You can put a 2.35 or 2.40 letterbox on a 4x3 or 16x9 recording, but there is no additional squeeze added on top of that (unless for some creative effect, like trying to fit some widescreen titles in a pan & scan transfer.)

If the letterboxed image doesn't look exactly 2.35, assuming your TV set is set-up properly, it could be because of overscan trimming the sides to something less than 2.35. You'd have to "windowbox" the transfer to solve that. But in terms of the image still looking squeezed on a 16x9 TV, check your menu options on the set.
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#4 coolbreeze

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Posted 28 February 2006 - 04:42 PM

Perhaps your 16x9 TV is set-up incorrectly -- mine has additional options for stretching and squeezing for people that want to fill a 16x9 set in different ways.

A DVD is standard def and can only have two types of signals: 4x3 or 16x9. That's it.


Hi David,
Thats what i thought too , however I have the same problems with off the shelf commercial dvds. Its not that the image has been "cropped" i.e its not an overscan issue, but its like the image has not been unsqueezed fully so the image is slightly taller than it should be and circles appear slightly oval, and the shape of the picture is similar in proportion to a 2:1 image - but nothing has been cropped if that makes sense? As all the monitors were Sony Im hoping that it might be something to do with whatever de-squeeze technology they employ, because im 99% sure that ive correctly set up both the dvd player and the monitor/tv.

Hi Stephen,
Could you explain what you mean by encoding the black letterbox areas?

Sincerely,
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#5 Thomas Worth

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Posted 28 February 2006 - 08:01 PM

First of all, we need to know if the DVDs in question are PAL or NTSC, and what type of DVD player you are playing them in.

NTSC DVD players will oftentimes play back PAL material, using a modified pulldown technique. However, they do not deal with the increased vertical resolution properly, making the video look as though it is stretched out. This is the case even when the DVD is encoded properly and both the DVD player and TV are set up correctly.

Another thing that would cause this problem is if DVD was authored incorrectly -- specifically, the MPEG2 streams were flagged by the encoder as 4:3 instead of 16:9. However, if your statement is true about the problem existing even with commercial DVDs, the point may be moot.
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#6 Dan Goulder

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Posted 28 February 2006 - 08:16 PM

If you're witnessing the same problem with every off the shelf DVD, then the problem is clearly in your playback chain. (player and/or monitor)

Edited by dgoulder, 28 February 2006 - 08:18 PM.

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#7 Stephen Williams

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Posted 01 March 2006 - 03:15 AM

Hi Stephen,
Could you explain what you mean by encoding the black letterbox areas?

Sincerely,


Hi,

When viewed on a 16x9 monitor there will be black top and bottom. This frame must be rendered with the area of black.

The 2.35 needs in effect to be 16x9 letterboxed to 2.35!

Stephen
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#8 David Mullen ASC

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Posted 01 March 2006 - 03:32 AM

My 16x9 HD LCD monitor has four Viewing Modes: Side Bar, Smart Stretch, Zoom, and Stretch.

The correct setting to view DVD's is "Stretch" so that the 16x9 anamorphic SD image fills the 16x9 screen, with any letterboxing in the recording correctly displayed.

If I set it to "Side Bar", the image has a squeeze to it and has black borders on the sides. If I then switch the "Smart Stretch", that image is stretched to fill 16x9 but it's still slightly squeezed and slightly zoomed into (Smart Stretch is designed to stretch 4x3 to fill 16x9, but with more stretching on the edges of the frame than the middle.) So perhaps your 16x9 monitor is set to this option, which will end up making the image look slightly squeezed.
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#9 coolbreeze

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Posted 01 March 2006 - 05:22 AM

My 16x9 HD LCD monitor has four Viewing Modes: Side Bar, Smart Stretch, Zoom, and Stretch.

The correct setting to view DVD's is "Stretch" so that the 16x9 anamorphic SD image fills the 16x9 screen, with any letterboxing in the recording correctly displayed.



Thanks again for the help guys. I have the same 4 options, albeit under different names, on my monitor too David. I also use the Wide (stretch) option but it still doesnt de-squeeze the image enough. All aspect ratios appear slightly taller then they should.
I'll revist the dvd players setup again:( and see if i have any joy. Thanks again.
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#10 David Mullen ASC

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Posted 01 March 2006 - 11:28 AM

The other question is whether you're attempting to play Region 1 DVD's in a Region 2 country -- the pixel ratio is different between NTSC and PAL and not all multi-region players compensate correctly.
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#11 Phil Rhodes

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Posted 01 March 2006 - 11:38 AM

Hi,

This has pretty much been covered.

One particularly confusing issue is that 2.35 letterboxed into 16:9 has more or less the same shaped picture as 16:9 letterboxed into 4:3, which can be confusing, but yes, if it's distorted, you are not doing something correctly.

Phil
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#12 David Mullen ASC

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Posted 01 March 2006 - 11:57 AM

I was assuming he had a 16x9 monitor, but if he had a 4x3 monitor, then yes, the image will look too squeezed and yet letterboxed still when viewing a 16x9 DVD with a 2.35 letterbox unless correctly set-up in the menu system (usually you have to select "4x3 Letterbox" in the main DVD player menu, not "16x9".)
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#13 coolbreeze

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Posted 01 March 2006 - 04:56 PM

I was assuming he had a 16x9 monitor, but if he had a 4x3 monitor, then yes, the image will look too squeezed and yet letterboxed still when viewing a 16x9 DVD with a 2.35 letterbox unless correctly set-up in the menu system (usually you have to select "4x3 Letterbox" in the main DVD player menu, not "16x9".)



Hi guys,

Just to confirm again i am using region 2 dvds on a region 2 dvd player and viewing on a 16x9 monitor with the tv set to Wide and the dvd player set to 16x9 mode - I have everything set up correctly no question there. Yet when i look at a 4x3 monitor side by side, with the dvd player set up to output 4x3 letterbox then the 4x3 monitor image image looks more correct to my eye.
Maybe i just need to get used to watching the larger size image of a 16x9 tv.
Thanks again for the help,
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