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General HD (720 / 1080) Acquisition
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Old June 24th, 2007, 10:48 PM   #1
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HD and 2.35 : 1

Just a question, does anyone shoot their HD productions in the 2.35 : 1 aspect ratio?

I personally love this aspect ratio and find that 16:9 isn't usually wide enough for effect in drama type stories. Do you crop the tops and bottoms off of your HD video to get this aspect ratio?

Is this something that is worth doing?
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Old June 24th, 2007, 11:15 PM   #2
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Jay:

I use it regularly, and love it. Someone posted a bunch of aperatures for different films a few months back, and I fashioned this one from it. I think I had to stretch it to fit the HDV. I attached the ones that were posted before, below.
Attached Images
File Type: psd Letterbox - Scope (2_35).psd (73.2 KB, 2062 views)
File Type: psd Letterbox - Flat Academy Aperature (1_85).psd (73.4 KB, 607 views)
File Type: psd Letterbox - Academy Aperature (1_37).psd (73.4 KB, 504 views)
File Type: psd Letterbox - Widescreen 16x9 (1_78).psd (73.4 KB, 626 views)
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Old June 25th, 2007, 04:09 AM   #3
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Never shot with an anamorphic lense, but I use a lot of 2.37:1 with 16:9 HDV video. Just crop/mask 135 pixels from the top and bottom. This will result in a 1440x810 image in a 1440x1080 box. The aspect ratio of the image will be 1920:810 = 2.37:1 on playback.

You can move the original 16:9 image a bit up and down to correct the original framing. It's very nice on wide shots, but can be ugly with extreme close ups.

Final output (without the bars) can be 1920x810, 1280x540, 768x324 or 640x270 for web/computer video.
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File Type: zip 237_mask.zip (2.0 KB, 408 views)
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Old June 25th, 2007, 08:35 AM   #4
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and I guess this is just a matter of putting black tape on the top and bottom portions of your camera lcd screen when recording, so that you can see the actual image that will be shown in the final film.


the thing that bugs me about just cropping the tops and bottoms for my master copy (which I definitely want to be 2:35:1) is that lets see I was going to render a 16:9 version for DVD's, this would contain more of the picture then the master, because the 16:9 version will have the cropping removed basically.

I'd much the prefer to have the 2:35:1 version as the master that contains all resolution possible, and then I can crop the sides to make it 16:9 or 4:3

Is there a way to record HD video so that all resolution goes to a 2:35:1 aspect ratio, how do these anamorphic lenses work? I only have an HV20 camera, although I was thinking about getting one of those mini35 kits.
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Old June 25th, 2007, 09:36 AM   #5
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I also use 2.37:1 aspect ratio because it gives nice even numbers.

1920x810
1280x540
854x360
720x270 anamorphic (4x3 source)
720x360 anamorphic (16x9 source)

Most widescreen Hollywood DVDs actually encode the movies as 720x360 anamorphic placed over a black 720x480. The video itself is encoded at 720x480 16x9 anamorphic but the video still is letterboxed so the amount of pixels from the movie itself is around 720x360. This is yet another of the many reasons why Hollywood DVD's encode better then normal footage. The black bars are still there but they do not take up very many bits at all since they are always the same solid color. The same will of course be true for HD-DVD or Blu-Ray. If you letterbox then for any given bitrate the quality will be better then if you were to encode at a full image of 16x9. This means either more video on the disk due to a lower bitrate needed or a higher quality product.

You could shoot with a 16x9 using a adapter designed to turn a 4x3 camera into a 16x9 camera and get around 2.37:1 but there are a few problems.
1. HDV2 is 1440x1080 anamorphic already and adding an adpter means the pixels are stretched from 1440 all the way up to 2560 pixels which means very soft details.
2. Most of these adapters are made for SD cameras so the optics are not the best for HD. On top of that you are trying to pull more detail out of the already strained 1/3" chips then what they were designed for.
3. All your shooting will have to be done with a anamorphic looking image which may be a little funky at first. This is because the stretched out image will still end up displayed on the 16x9 LCD screen or viewfinder.
4. There is no to deliver that type of video. DVD, HD-DVD or Blu-Ray do not have a 2.3# anamorphic mode. This means you will end up shrinking down to a lower resoltuion with letterbox bars anyway. You would almost be better off just shooting 16x9 and crop if you want 2.3#:1 and keep the 16x9 if you really want 16x9.
5. I'm not sure if any NLE's are really setup for this type of pixel ratio. I'm sure in some custom programs you could force the format but the performance may not be as good. You may end up editing the footage as anamorphic which will look very odd for any graphics or titles you would add.
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Old June 25th, 2007, 03:52 PM   #6
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Confused...

Thomas, you got me confused on this one. What do you exactly mean by: "Most widescreen Hollywood DVDs actually encode the movies as 720x360 anamorphic placed over a black 720x480. The video itself is encoded at 720x480 16x9 anamorphic but the video still is letterboxed so the amount of pixels from the movie itself is around 720x360. This is yet another of the many reasons why Hollywood DVD's encode better then normal footage."

I thought the beauty of 16x9 is the extra data contained in the full 480 lines of vertical resolution... How can 360 lines resized in the player to 480 produce a better picture than full 480 lines compressed to 360? How can you encode the video at 720x480 16x9 anamorphic and still letterbox it?

Please elaborate.
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Old June 26th, 2007, 12:42 AM   #7
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watch a DVD on a widescreen TV and you will notice it is still letterboxed. The letterbox is of course smaller then if you watched on a 4x3 TV but it is still there.

a lot of movies are 2.35:1 aspect ratio. DVD can be widescreen but 16x9 is still not as wide as 2.35:1. This means in order for a movie to be viewed the way it was meant to be viewed the 2.35:1 has to be somehw placed in a 16x9 format.

viewing a full 16x9 amount of pixels will only work if your source is 16x9.

2.35:1 compared to 16x9 is very much like 16x9 compared to 4x3.

Some movie DVD's could in fact be encoded as true 16x9 but then they would still be cutting off a section of the image from the film much like how 4x3 DVD's will cut off some of the area of the film.

The same rules apply here. If you have a 2.35:1 source with a 16x9 recording format then you will either have to letterbox it to fit or crop off the sides.

Some things to remember:
1. A 16x9 DVD at 720x480 pixels will look like a image that is around 854x480 pixels. This is due to the anamorphic pixels.
2. A 2.35:1 film source made to fit inside this 854x480 space would shrink down to around 854x360 pixels.
3. A DVD must have 480 vertical pixels so black bars must be added to encode the mpeg2 file if the vertical resolution is smaller then 480.
4. The video is encoded at 720x480 but only the 720x360 chunk of pixels in the middle actually show any pixels other then solid black.
5. It would have been nice if the DVD specs allowed a 2.35:1 aspect ratio for encoded material but sadly they do not. They end up faking it by half using the widesceen nature of 16x9 and the other half by still doing a small amount of letterboxing.
6. If your DVD was not 16x9 anamorphic and was only 4x3 then in order to put a 2.35:1 movie inside of the 720x480 pixels you would down size the film to 720x270 pixels and letterbox the top and bottom to make it fit in the 720x480 video. Because DVD can be a 16x9 format however these 2.35:1 movies get to use 720x360 pixels of the 720x480 to show the film image instead of just using 720x270 of the 720x480 pixels.
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Old June 26th, 2007, 06:40 AM   #8
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Got you. You're talking in the context of the 2.35:1 aspect ratio.

Footage shot as true 16x9, edited as 16x9 and encoded as 16x9 anamorphic DVD is in fact 720x480 pixels all the way (with no black bars) and will show up correctly on a 16x9 television monitor. You only need letterboxing for a 16x9 DVD if your footage was 2.35:1.
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